Packaging system comprising cellulosic web with a permeant barrier or contaminant trap

Nonwoven cellulosic fiber webs including, paperboards and corrugated paper board, etc., are described containing a barrier layer that can act both as a barrier to the passage of a permeant and as a trap for contaminant materials that can arise in new materials or from the recycle of fiber in the manufacture of paperboard. The effective material which acts as a trap or barrier is a cyclodextrin compound, substantially free of an inclusion complex compound. The cyclodextrin barrier layer can be corrugated or sheet laminated with or on the cellulosic web. Alternatively, the cyclodextrin material can be included in a coating composition that is coated on the surface or both surfaces of the cellulosic web after web formation. Further, the cyclodextrin material can be included in a thermoplastic film that can be used as one layer in a bilayer or multilayer laminate containing a cellulosic web.

FIELD OF THE INVENTION 
The invention relates to improved rigid or semirigid cellulosic packaging 
material, including chipboard, boxboard, paperboard or cardboard 
materials, which have permeant barrier or contaminant trapping properties. 
The preferred barrier paperboard material can reduces the passage of 
permeant materials from the ambient atmosphere through the paperboard into 
packaging contents. Further, any mobile or volatile, organic contaminant 
material from the environment, present within the paperboard or as a 
paperboard component, derived either from a source of cellulosic material, 
a printing chemical, a coating chemical or from any contaminant in 
intentionally recycled material, can be trapped by the active barrier 
materials within the paperboard packaging structure. 
The invention includes a barrier structure comprising at least one layer of 
a cellulosic material with at least one layer of a barrier or a barrier 
layer containing an active barrier component. The packaging structure can 
have other layers useful in packaging systems. The layer of cellulosic 
material is structural and is manufactured or oriented to have a defined 
product side and a defined exterior side. 
BACKGROUND OF THE INVENTION 
Cellulosic materials such as a paperboard, a boxboard, a cardboard or a 
chipboard consists of relatively thick, compared with paper, sheet 
materials that are comprised of bonded, small discrete fibers comprising 
cellulose. Such fibers are typically held together by secondary bonds 
that, most probably, are hydrogen bonds. To form a cellulosic sheet, fiber 
is formed into a rough web or sheet on a fine screen from a water 
suspension or dispersion of fiber and is combined with fiber additives, 
pigments, binder material, secondary binder materials or other components. 
After the sheet is formed on a fine screen, the rough sheet is then dried, 
calendared and further processed to result in a finished sheet having a 
controlled thickness, improved surface quality, one or more coating 
layers, a fixed moisture content, etc. Further, after sheet formation the 
paperboard can be further coated, embossed, printed or further processed 
before rolling and distribution. Paperboard, boxboard, chipboard or 
cardboard typically has a caliper (thickness) of greater than about 0.30 
mm (in the united kingdom greater than about 0.25 mm). Paper with a basis 
weight (grammage) generally above 250 g-m.sup.-1 (51 lbs-10.sup.3 
ft.sup.-2) is considered paperboard under ISO standards. Typically, paper 
is considered a sheet-like material having a thickness of less than about 
0.25 mm, often less than 0.1 mm. 
Paperboard, boxboard, chipboard and cardboard are made in many types and 
grades to service a variety of uses. The final finishes of paperboard can 
be rough or smooth, can be laminated with other materials, but are 
typically thicker, heavier and less flexible than conventional paper 
materials. Paperboard can be made both from primary sources of fibers and 
from secondary or recycled fibrous materials. The fiber used in making 
paperboard largely comes directly from the forestry industry. However, 
increasingly paperboard is made from recycled or secondary fiber derived 
from paper, corrugated paperboard, woven and nonwoven fabric, and similar 
fibrous cellulosic materials. Such recycled fibrous material inherently 
contains finishing material such as inks, solvents, coatings, adhesives, 
residue from materials the fiber source contacted and other sources of 
contamination. These recycled finishing materials in addition to freshly 
applied finishing materials contain residual volatile organics that can 
pose some threat of contamination to the stored contents of containers 
made from such recycled materials. 
The main components used in the manufacture of paper products are 
mechanical/semi-mechanical wood pulp, unbleached Kraft chemical wood pulp, 
white chemical wood pulp, waste fiber, secondary fiber, non-wood fibers, 
recycled woven and non-woven fibers, fillers and pigments. Many varieties 
of wood pulp used are derived from both hard and softwoods. The chemical 
properties and composition of paperboard are determined by the types of 
fibers used and by any non-fiber substances incorporated in or applied on 
the surface of the paper during paper making or subsequent paper 
converting operations. Paper properties that are affected directly by the 
fiber's chemical compositions include color, opacity, strength, 
permanence, and electrical properties. 
In the manufacture of paperboard, barrier coatings are often required to 
improve resistance to the passage of water, water vapor, oxygen, carbon 
dioxide, hydrogen sulfide, solvents, greases, fats, oils, odors, recycled 
contaminants or other miscellaneous chemicals through the paperboard 
material. Water (liquid) barriers are known and can change the wetability 
of the paper surface using sizing agents. A grease or oil barrier can be 
provided by hydrating the cellulosic fibers to form a pinhole free sheet 
or by coating the paper with a continuous film of a material that is fat 
or grease resistant (lipophobic). Gas or vapor barriers are formed using a 
continuous film of a suitable material that can act as a barrier to the 
specific gas or vapor. Paperboard is also often coated or printed to 
improve lifetime and utility. 
A variety of film materials have been developed as barriers to the passage 
of water vapor, oxygen or other permeants. Brugh Jr. et al., U.S. Pat. No. 
3,802,984, teach moisture barriers comprising a laminate of a cellulosic 
sheet and a thermoplastic material. Dunn Bolter et al., U.S. Pat. No. 
3,616,010, teach a moisture barrier comprising a laminated and corrugated 
paperboard and a lamination layer of a thermoplastic bag stock. Brugh Jr. 
et al., U.S. Pat. No. 3,886,017, teach a moisture barrier in a container 
comprising a laminate of high and low density cellulosic sheets within 
thermoplastic film. Willock et al., U.S. Pat. No. 3,972,467, teach 
improved paperboard laminates for containers comprising a laminate of 
paperboard polymer film and an optional aluminum foil layer. Valyi, U.S. 
Pat. No. 4,048,361, teaches packaging containing a gas barrier comprising 
a laminate of plastic cellulosic and other similar materials. Gibens et 
al., U.S. Pat. No. 4,698,246, teach laminates comprising paperboard 
polyester and other conventional components. Ticassa et al., U.S. Pat. No. 
4,525,396, teach a pressure resistant paper vessel comprising a barrier 
film laminate having gas barrier properties prepared from paperboard 
thermoplastic films, paper components and other conventional elements. 
Cyclodextrin materials and substitute cyclodextrin materials are also 
known. 
Further, Pitha et al., U.S. Pat. No. 5,173,481 and "synthesis of chemically 
modified cyclodextrins," Alan P. Kroft et al., Tetrahedron Reports No. 
147; Department of Chemistry, Texas Tech University, Ludwig, Tex., 79409, 
USA, (Oct. 4, 1982), pp. 1417-1474. Pitha et al. disclose cyclodextrins 
and substituted cyclodextrins. The major use of cyclodextrin materials is 
in formation of an inclusion complex for the delivery of an inclusion 
compound to a use locus. The cyclodextrin material has a hydrophobic 
interior pore that is ideal for complexing a variety of organic compounds. 
Unmodified cyclodextrin inclusion complex materials have been used in 
films, see Japan Patent Application No. 63-237932 and Japanese Patent 
Application No. 63-218063. The use of cyclodextrin inclusion compounds is 
discussed in detail in "Cyclodextrin Inclusion Compounds in Research and 
Industry", Willfrom Saenger, Angew. Chem. Int. Ed. Engl., Vol. 19, pp. 
344-362 (1980). The cyclodextrin inclusion compounds are used in a variety 
of delivery applications. Materials including deodorants, antibacterial 
materials, antistatic agents, eatable oils, insecticides, fungicides, 
deliquescent substances, corrosion inhibitors, flavor enhancing compounds, 
pyrethroids, pharmaceutical and agricultural compounds, etc. can be 
delivered. Such applications are disclosed in a variety of patents. 
Exemplary patents include Shibani et al., U.S. Pat. Nos. 4,356,115; 
4,636,343; 4,677,177; 4,681,934; 4,711,936; 4,722,815; and others. 
Yashimaga, JP 4-108523, teaches a permselective membrane used for 
separation of chiral compounds using a polyvinyl chloride film containing 
high loadings of a substituted cyclodextrin and a plasticizer. Yoshenaga, 
JP 3-100065, uses an unsubstituted cyclodextrin in a film layer. Nakazima, 
U.S. Pat. No. 5,001,176; Bobo Jr. et al., U.S. Pat. No. 5,177,129; and 
others use cyclodextrin materials to act as an inclusion complex for film 
stabilizing components. Zejtli et al., U.S. Pat. No. 4,357,468 shows one 
specific application of the use of cyclodextrin materials as servants in 
separation techniques. The particular cyclodextrin material is a 
polyoxyalkylene substituted material used in separation schemes. 
Many alleged barrier materials have been suggested in the art but currently 
there is no suitable material that can act as a barrier for the large 
variety of potential contaminants that can pass through packaging 
materials into the contents of the package. Further, the packaging 
material itself can be a source of permeants. Many paperboard materials, 
particularly those containing recycled fibers can contain significant 
levels of volatile contaminants. Certain food products are especially 
susceptible to absorbing volatile organoleptic chemicals. These foods 
include milk and other liquids stored within paperboard cartons, breakfast 
cereals and crackers comprising grain products, and confectionary products 
containing chocolate. Candies including chocolate and the high fat 
confectionaries can absorb larger proportions of off flavors. Absorption 
of these volatiles can mean a shortened shelf-life and reduced sensory 
quality. The contaminants are derived from chemical components used in 
paper product manufacture and comprise a component of an ink, an adhesive, 
a coating, a filler, a sizing, a binder, a polymer, a lubricant, a 
preservative, a process aid, etc. 
Accordingly, a substantial need exists for the development of new 
paperboard materials or laminates from virgin fiber, recycled fiber or 
mixtures thereof. The paperboard contains a barrier layer that can act 
both as a barrier to the passage of contaminants and as a trap for 
contaminant materials that can arise in new materials or from the recycle 
of fiber in the manufacture of paperboard. 
BRIEF DISCUSSION OF THE INVENTION 
We have found that the barrier properties of non-woven cellulosic webs can 
be substantially improved with a barrier layer comprising cyclodextrin and 
a diluent. The barrier layer comprising a cyclodextrin and a diluent can 
be formed using any available layering technology. Examples of useful 
layer formation processes include lamination, coextrusion, solution 
coating, suspension coating, spraying, printing, etc. The preferred modes 
for forming the cyclodextrin/diluent layer on the paperboard comprises a 
coextrusion or a coating formed from an aqueous solution. Mixtures and 
coatings are typically manufactured by extruding by a thermoplastic layer 
comprising a thermoplastic as a diluent with the cyclodextrin dissolved or 
dispersed within the thermoplastic melt extruded layer. The paperboard is 
typically coextruded with the layer and is immediately contacted with the 
extruded thermoplastic and becomes bonded to the thermoplastic 
cyclodextrin barrier layer. An alternative preferred method of forming the 
barrier layer is to coat the cellulosic layer with an aqueous or other 
solvent born solution or dispersion of the cyclodextrin with a diluent. 
The diluent can comprise a variety of inert carrier or film forming 
agents. Such materials include starch, modified starch, cellulose, 
modified cellulose, film forming polymers from natural or synthetic 
origin, etc. The barrier coating can be formed from a relatively high 
concentration of diluent and cyclodextrin in preferably an aqueous 
solution. The concentration of the cyclodextrin in the coating or in the 
thermoplastic coextruded layer is sufficient to provide a barrier to 
permeants or to trap paperboard contaminants in the barrier layer. One 
advantage of the aqueous coating option is the ability to use an 
unsubstituted cyclodextrin in the barrier layer. Substituted cyclodextrin 
is typically required for compatibility with melt thermoplastic processing 
while the unsubstituted cyclodextrin can easily be included in an aqueous 
coating composition without chemical modification. There appears to be a 
synergistic effect which results from dispersing the cyclodextrin within 
starch and the use of such a layer in a two, three or more layer 
structure. The passage of permeants through or the release of contaminant 
permeants from a cellulosic web, can be reduced or prevented by forming 
the cellulosic web with a barrier layer containing an effective permeant 
or contaminate trapping amount of a cyclodextrin or a substituted or 
derivatized cyclodextrin compound. 
The cellulosic web comprises a structural layer with a defined interior or 
product side and a defined exterior side. The product side possesses a 
barrier layer comprising a coating comprising a cyclodextrin or layer 
comprising a diluent such as starch, cellulose or modified cellulose and a 
cyclodextrin compound while the exterior side has a layer comprising a 
clay coating, printing, etc. Optionally, the barrier layer comprises a 
thermoplastic polymer layer comprising substituted cyclodextrin. 
Optionally, the web can also contain thermoplastic polymer layers without 
added cyclodextrins. The finished web typically comprises an exterior 
finish coating. 
Accordingly, the invention can be found in a nonwoven cellulosic fiber web 
having improved barrier trap properties in the presence of a permeant or 
contaminant, the web comprising a structural layer comprising a continuous 
array of randomly oriented cellulosic fiber having a product side and an 
exterior side; on the product side, a barrier layer comprising a 
cyclodextrin compound and a diluent; and on the exterior side, a layer 
comprising a clay; wherein the cyclodextrin compound is subsequently free 
of an inclusion complex compound and can act as a barrier to the passage 
of a permeant from the ambient environment or can act as a trap of a 
contaminant arising from the web. 
Further, the invention can also be found in a nonwoven cellulosic fiber web 
having improved barrier trap properties in the presence of a permeant or 
contaminant, the web comprising a structural layer comprising a continuous 
array of randomly oriented cellulosic fiber having a product side and an 
exterior side; on the product side, a barrier layer comprising a 
cyclodextrin compound and a starch modified starch, cellulosic a modified 
cellulosic diluent; on the exterior side, a layer comprising a clay layer 
and a printed layer; wherein the cyclodextrin compound is subsequently 
free of an inclusion complex compound and can act as a barrier to the 
passage of a permeant from the ambient environment or can act as a trap of 
a contaminant arising from the web. 
Further, the invention can also be found in a nonwoven cellulosic fiber web 
having improved barrier trap properties in the presence of a permeant or 
contaminant, the web comprising a structural layer comprising a continuous 
array of randomly oriented cellulosic fiber having a product side and an 
exterior side; on the product side, a barrier layer comprising a 
cyclodextrin compound and a coextruded thermoplastic polymer diluent; on 
the exterior side, a layer comprising a clay layer and a printed layer; 
wherein the cyclodextrin compound is subsequently free of an inclusion 
complex compound and can act as a barrier to the passage of a permeant 
from the ambient environment or can act as a trap of a contaminant arising 
from the web. 
A preferred embodiment of the invention comprises a nonwoven cellulosic 
fiber web having improved coating barrier trap properties in the presence 
of a permeant or contaminant, the web comprising a structural layer with a 
thickness of 0.25 to 1 mm, preferably 0.4 to 0.8 mm, comprising a 
continuous array of randomly oriented cellulosic fiber having a product 
side and an exterior side; on the product side, a barrier layer comprising 
10 to 60 gm-1000 ft.sup.-2, comprising 1 to 60 wt. % of a cyclodextrin 
compound and a coatings diluent; on the exterior side, a layer comprising 
a clay layer with a thickness of 20 to 80 microns and a printed layer 
comprising 0.5 to 1 lbs-1000 ft.sup.-2 ; wherein the cyclodextrin compound 
is subsequently free of an inclusion complex compound and can act as a 
barrier to the passage of a permeant from the ambient environment or can 
act as a trap of a contaminant arising from the web. The structure can 
have a finish coating add-on comprising a coating of about 0.05 to 1 
lbs-1000 ft.sup.-2 on either or both sides. 
Another preferred embodiment involves a nonwoven cellulosic fiber web 
having improved extruded film barrier trap properties in the presence of a 
permeant or contaminant, the web comprising a structural layer with a 
thickness of 0.25 to 1 mm, preferably 0.4 to 0.8 mm, comprising a 
continuous array of randomly oriented cellulosic fiber having a product 
side and an exterior side; on the product side, a barrier layer comprising 
a an extruded film coating comprising a thickness of 0.3 to 1.5 mil, 
comprising 0.1 to 60 wt. % of a cyclodextrin compound in a thermoplastic 
diluent; on the exterior side, a layer comprising a clay layer with a 
thickness of 20 to 80 microns and a printed layer comprising 0.5 to 1 
lbs-1000 ft.sup.-2 add-on; wherein the cyclodextrin compound is 
subsequently free of an inclusion complex compound and can act as a 
barrier to the passage of a permeant from the ambient environment or can 
act as a trap of a contaminant arising from the web. The structure can 
have a finish coating add-on comprising a coating of about 0.05 to 1 
lbs-1000 ft.sup.-2 on either or both sides. 
The cyclodextrin compound used in this role is a cyclodextrin compound, 
substantially free of an inclusion complex compound, which can act as a 
trap or barrier to the passage of a permeant or contaminate through the 
web or from the web into the container. The improved cellulosic web 
operates by establishing a sufficient concentration of cyclodextrin 
compound, free of an inclusion complex compound, in the path of any 
permeant or contaminate passing through or passing from the cellulosic 
web. The cyclodextrin compounds that can be used in the invention include 
unsubstituted cyclodextrins having no intentionally formed substituents on 
the ring hydroxyls of the cyclodextrin molecule. The cyclodextrin 
compounds that can be used in the invention also include cyclodextrins 
that contain substituents on the available primary or secondary hydroxyl 
groups of the cyclodextrin rings. Such barrier layers can be coated, 
sprayed, corrugated or sheet laminated with or on the cellulosic web. The 
cyclodextrin material can be included in a coating composition that is 
coated on a surface or both surfaces of the cellulosic web after web 
formation. Such coatings can be formed in a variety of networks including 
extrusion coatings, Rotogravure coatings, etc. Further, the cyclodextrin 
material can be included in a thermoplastic film that can be used as one 
layer in a bilayer or multilayer laminate containing a cellulosic web. 
Such a laminate can contain additional layers of cellulosic materials or 
other types of barrier layers. The laminate can contain additional layers 
of a film material that can contain the cyclodextrin barrier or trap 
material or can optionally contain other ingredients. The cyclodextrin can 
be part of the film by extrusion or by coating a flexible cyclodextrin 
layer in the film. 
For the purpose of this application, the term "web" refers to any non-woven 
sheet-like assembly of randomly oriented cellulosic fiber. Such webs are 
typically continuous webs and contain no substantial apertures. Such webs 
can take the form of thin paper sheets, heavy paper, cardboard, 
paperboard, card stock or chipboard stock or laminates made from paper, 
paperboard, thermoplastic webs or coated sheets thereof. 
For the purpose of this application and claims the term "permeant" refers 
to a chemical compound or composition that, at ambient temperatures and 
pressures, can be transported through at least a portion of the cellulosic 
web. Such permeants can arise in the ambient atmosphere or environment, 
can be absorbed on one surface of the web and be transported through the 
cellulosic web interior to be released from the opposite web surface. 
Additionally, such permeants can arise as contaminants in the web or from 
ingredients used in manufacturing, and can be transported from the 
interior of the web to a surface of the web for release either into the 
ambient atmosphere or into any internal enclosed space surrounded by the 
web. As used in this application, the term "trap" refers to a cyclodextrin 
or cyclodextrin derivative that can act to complex and immobilize, within 
the web, any impurity in the web arising from impurities present during 
the paper making process. The impurities are included in the cyclodextrin 
molecule, totally or in part, without covalent bonding in the central pore 
of the molecular structure. Such impurities can arise from contamination 
of the source of cellulosic fiber, for example, recycle of used cellulosic 
materials or by contamination arising from any other source. The term 
"barrier" means the prevention of transport of a permeant from one surface 
of a cellulosic web through the interior of the web for release from the 
opposite surface of the web. A "packaging system" comprises a two, three, 
or more layer structure having at least a cellulosic web. The layers 
comprise a barrier layer or trap used with either a printing layer, a clay 
layer, a film laminate, or any other useful layer in common packaging.

DETAILED DISCUSSION OF THE INVENTION 
Cellulosic Web 
Paper or paperboard has a thin layered network of randomly oriented fibers 
bonded together through hydrogen bonding. Paper or paperboard products are 
made from bondable fibrous material and form a layered structure of fiber 
in random orientation. Cellulosic fibers are the prime material for 
papermaking, however, any paper or paperboard material can contain other 
fibers in combination with cellulosic materials. Paper and paperboard are 
made from aqueous suspensions of fibers. Cellulosic fibers are readily 
dispersed or suspended in water that serves as a carrier before the 
suspension is applied to a screen in the papermaking process. The primary 
source of fibrous materials used in paperboard manufacturing include wood 
pulp, waste paper such as newspaper, corrugated paperboard, deinked fiber, 
cotton, lint or pulp, and other materials. Waste or recycled paper also 
known as secondary fiber is becoming more and more important in paper and 
paperboard manufacture. The percentage of paperboard recycle as secondary 
fiber has substantially increased since 1980 becoming a major source of 
fiber. Cellulosic pulp typically made from hard and soft wood but can be 
made from any planned source of cellulosic material include ground wood 
pulp, pressurized ground wood pulp, ground wood pulp from chips, refinery 
mechanical pulp, chemi-refiner mechanical pulp, chemi thermomechanical 
pulp, thermochemical pulp, sodium sulfite treated TMP pulp, sulfonated 
chip and mechanical pulp, tandem thermomechanical pulp. In any of these 
processes, water elevated temperature chemical additives and other 
materials are added to chip wood to reduce the wood to a useful pulp 
material. In the recycle or pulping of secondary fibers, the used fiber is 
typically introduced into an aqueous bath containing a variety of 
chemicals that separate the cellulosic components of the paper into fiber 
and remove ink coatings and other materials in the recycled paper. 
Paper or paperboard is made, from virgin or recycled fiber or both, in a 
typical fourdrinier paper process using a fourdrinier paper machine. The 
fourdrinier paper machine typically comprises a head box for the clean 
pulp, a screen section for initial web formation rollers and presses in 
connection with the fourdrinier screen that removes additional water from 
the rough web. Presses that regulate thickness and surface quality and 
finally a take-up reel or storage portion. In the fourdrinier process, a 
stock aqueous pulp enters the head box and delivers a ribbon of aqueous 
stock to the fourdrinier water at a uniform dilution thickness and add-on 
speed. The head box contains a slice, a narrow opening in the head box 
through which the stock flows in a controlled thickness onto a wire mesh. 
The wire is a continuous belt of woven material originally metal wire but 
now most frequently a plastic web. The wire travels over a series of 
rollers that both keep the wire level and remove water from the rough 
cellulosic web. Water is removed from the pulp first by gravity, then by 
low pressure and finally by suction devices located under the wire. The 
paper web leaves the wire at this point. The wire in a continuous loop 
returns to the head box for additional stock. The rough cellulosic web, 
when in the press section comprising hard rolls that squeeze the paper 
gently to remove water, is compressed to promote bonding and to form a 
rough thickness. The cellulosic web then passes through and around a 
series of steam filled drums called dryer cans that remove residual water 
by evaporation. In the dryer section, chemicals can be added in a size 
press to the surface of the web. At the finishing end of the machine are 
calendar reel and rewinder rolls that act to press the sheet, to smooth 
the sheet, and to control final thickness. After finishing, the web is 
wound on a reel for further transport to use or further treatment. 
The dried paper webs can be modified to improve properties. Both internal 
and external sizings can be used to prove water resistance. Wet strength 
agents and bonding additives can be used in forming the cellulosic web to 
aid in retaining wet strength. The web can be physically modified using a 
calendaring process. Machine calendar is a stack of steel rolls at the dry 
end of a paper making machine that compresses the web forming a flatter, 
smoother surface. This flat surface accepts print, feeds more smoothly in 
use in machines and can also adjust thickness. The surface of the web can 
also be pigmented with a pigmented coating or layer. Pigmented coatings 
and layers typically comprise a pigment and a binder material. Typical 
pigments include a clay, calcium carbonate, titanium dioxide or plastic 
pigments. A preferred pigment material is clay. The pigments are typically 
applied in the form of an aqueous suspension or dispersion of pigment 
material in the binder or adhesive composition. Typically binders or 
adhesives include starch, proteins, styrene butadiene dispersions or 
lattices, polyvinyl acetate and lattices, acrylic lattices and others. 
Coatings are applied with conventional application equipment that ensure 
the coating is applied uniformly to the entire surface, the amount of 
coating obtains the appropriate or desired thickness or coat weight on the 
entire web and results in a smooth surface finish. The exterior surface of 
the web can include a printed layer. 
The cellulosic webs of the invention include newsprint on coated ground 
wood paper, coated papers, uncoated free sheets, writing paper, envelope 
stock, kraft stock, bristol board, tabulated card stock, unbleached 
packaging, wrapping shipping sack stock, bag and sack stock, packaging 
unbleached craft wrapping stock, wrapping stock, shipping stock, waxing 
stock, solid wood pulp paperboard, unbleached craft paperboard, unbleached 
liner board, carton-type board stock, milk carton board stock, heavy 
weight cup stock, bleached paperboard stock, recycled paperboard, 
construction paper and board, structural insulating board and others. If 
paperboard is used in the invention, it is preferred that it be a 
paperboard with thickness of about 0.25 to 1 mm, preferably, a caliper of 
about 15 to 30 (about 0.4 mm to 0.8 mm; 0.15 inches to 0.30 inches), 
preferably, 16 to 28 point (0.16 inches to 0.28 inches). 
The paperboard of the invention can also include corrugated paperboard 
materials. Corrugated paperboard is typically made by first manufacturing 
a single faced structure comprising a fluted medium adherently attached to 
a top liner making a single faced board (one flat layer bonded to a 
corrugated sheet). In manufacturing the single faced material, the web is 
first corrugated and then combined with the liner board using commonly 
available starch-based corrugating adhesives. Once combined in the single 
facer, the corrugated material and the liner are permitted to bond and 
dry. After the single facer is complete, it is then bonded to a second 
liner using a similar corrugating adhesive material. To make double wall 
board or further layers of corrugated paperboard, similar process steps 
are repeated until a sufficient number of layers is complete for the 
desired application. 
The paperboard and corrugated paperboard materials of the invention can be 
used to manufacture various types of packages. Folded packages including 
corrugated container boxes, folding carton can be made from corrugated 
medium solid bleached or unbleached paperboard. Flexible containers can be 
made as bags, sacks, pouches, wrappers and labeled items made from paper 
laminates comprising a web film or foil clay coated paper laminates, 
thermoplastic material coated paper laminates or multilayer paper 
laminates. 
Cyclodextrin 
The cellulosic webs of the invention contain a cyclodextrin or a 
substituted or derivatized cyclodextrin in a barrier or trap layer. The 
barrier or trap layer comprises cyclodextrin in a layer with a diluent, in 
a coating or in a film laminate. The cyclodextrin material is compatible 
with the diluent, coating or thermoplastic polymer. For this invention, 
compatible means that the cyclodextrin material can be uniformly dispersed 
into the layer, can retain the ability to trap or complex permeant 
materials or polymer impurity, and can reside in the layer without 
substantial reductions in the important packaging characteristics of the 
web. Compatibility can be determined by measuring web characteristics such 
as tensile strength, tear resistance, permeability or transmission rates 
for permeants, surface smoothness, etc. 
Cyclodextrin is a cyclic oligosaccharide consisting of at least five, 
preferably at least six glucopyranose units joined by .alpha.-1,4 
linkages. Although cyclodextrin with up to twelve glucose residues are 
known, the three most common homologies (.alpha. cyclodextrin, .beta. 
cyclodextrin and .gamma. cyclodextrin) having six, seven and eight 
residues have been used. Cyclodextrin is produced by a highly selective 
enzymatic synthesis. They consist of six, seven, or eight glucose monomers 
arranged in a torus or donut shaped ring, which are denoted .alpha., 
.beta., or .gamma. cyclodextrin respectively (See FIG. 1). The specific 
coupling of the glucose monomers gives the cyclodextrin a rigid, truncated 
conical molecular structure with a hollow interior of a specific volume. 
This internal cavity, which is lipophilic (i.e., is attractive to 
hydrocarbon materials in aqueous systems and is hydrophobic) when compared 
to the exterior, is a key structural feature of the cyclodextrin, 
providing the ability to the hydrocarbon portion of complex molecules 
(e.g., aromatics, alcohols, alkyl halides and aliphatic halides, 
carboxylic acids and their esters, etc.). The complexed molecule must 
satisfy the size criterion of fitting at least partially into the 
cyclodextrin internal cavity, resulting in an inclusion complex. 
______________________________________ 
CYCLODEXTRIN TYPICAL PROPERTIES 
PROPERTIES .alpha.-CD .beta.-CD 
.gamma.-CD 
______________________________________ 
Degree of 6 7 8 
Polymerization 
(n = ) 
Molecular Size (A.degree.) 
inside diameter 5.7 7.8 9.5 
outside diameter 13.7 15.3 16.9 
height 7.0 7.0 7.0 
Specific Rotation [a].sup.25.sub.D +150.5 +162.5 +177.4 
Color of iodine 
Blue Yellow Yellowish 
complex Brown 
Solubility in water 
14.50 1.85 23.20 
(g/100 ml) 25.degree. C. 
Distilled Water 
______________________________________ 
The oligosaccharide ring forms a torus, that can be visualized as a 
truncated cone, with primary hydroxyl groups of each glucose residue lying 
on a narrow end of the torus. The secondary glucopyranose hydroxyl groups 
are located on the wide end. 
The parent cyclodextrin molecule, and useful derivatives, can be 
represented by the following formula (the ring carbons show conventional 
numbering) in which the vacant bonds represent the balance of the cyclic 
molecule: 
##STR1## 
wherein R.sub.1 and R.sub.2 are primary or secondary hydroxyl as shown. 
Cyclodextrin molecules possess several sites available for reaction with a 
chemical reagent. These sites include the primary hydroxyl at the six 
position of the glucose moiety and the secondary hydroxyls in the two and 
three positions. Because of the geometry of the cyclodextrin molecule, and 
the chemistry of the ring substituents, all hydroxyl groups are not equal 
in reactivity. However, with care and effective reaction conditions, the 
cyclodextrin molecule can be reacted to obtain a derivatized molecule 
having all hydroxyl groups derivatized with a single substituent type. 
Such a derivative is a persubstituted cyclodextrin. Cyclodextrin with 
selected substituents (i.e.) substituted only on the primary hydroxyl or 
selectively substituted only at one or both the secondary hydroxyl groups 
can also be synthesized if desired. Further directed synthesis of a 
derivatized molecule with two different substituents or three different 
substituents is also possible. These substituents can be placed at random 
or directed to a specific hydroxyl. For the purposes of this invention, 
the cyclodextrin molecule needs to contain sufficient compatible 
substituent groups on the molecule to insure that the cyclodextrin 
material can be uniformly dispersed into the cellulosic material. Both 
substituted an non-substituted cyclodextrin and mixtures thereof can be 
used as a barrier or trap component. The contaminant or permeant becomes 
held within the central pore or cavity of the molecule. 
Apart from the introduction of substituent groups on the cyclodextrin 
hydroxyls, other molecule modifications can also be used. Other 
carbohydrate molecules can be incorporated into the cyclic backbone of the 
cyclodextrin molecule. The primary hydroxyl can be replaced using SN.sub.2 
displacement, oxidized dialdehyde or acid groups can be formed for further 
reaction with derivatizing groups, etc. The secondary hydroxyls can be 
reacted and removed leaving an unsaturated group to which can be added a 
variety of known reagents that can add or cross a double bond to form a 
derivatized molecule. Further, one or more ring oxygen of the glycan 
moiety can be opened to produce a reactive site. These techniques and 
others can be used to introduce compatibilizing substituent groups on the 
cyclodextrin molecule. 
The preferred preparatory scheme for producing a derivatized cyclodextrin 
material, having a functional group compatible with the coatings, 
diluents, thermoplastic polymer, involves reactions at the primary or 
secondary hydroxyls of the cyclodextrin molecule. Broadly we have found 
that a broad range of pendant substituent moieties can be used on the 
molecule. These derivatized cyclodextrin molecules can include acylated 
cyclodextrin, alkylated cyclodextrin, cyclodextrin esters such as 
tosylates, mesylate and other related sulfo derivatives, hydrocarbyl-amino 
cyclodextrin, alkyl phosphono and alkyl phosphato cyclodextrin, imidazolyl 
substituted cyclodextrin, pyridine substituted cyclodextrin, hydrocarbyl 
sulfur containing functional group cyclodextrin, silicon-containing 
functional group substituted cyclodextrin, carbonate and carbonate 
substituted cyclodextrin, carboxylic acid and related substituted 
cyclodextrin and others. The substituent moiety must include a region that 
provides compatibility to the derivatized material. 
Acyl groups that can be used as compatibilizing functional groups include 
acetyl, propionyl, butyryl, trifluoroacetyl, benzoyl, acryloyl and other 
well known groups. The formation of such groups on either the primary or 
secondary ring hydroxyls of the cyclodextrin molecule involve well known 
reactions. The acylation reaction can be conducted using the appropriate 
acid anhydride, acid chloride, and well known synthetic protocols. 
Peracylated cyclodextrin can be made. Further, cyclodextrin having less 
than all of available hydroxyls substituted with such groups can be made 
with one or more of the balance of the available hydroxyls substituted 
with other functional groups. 
Cyclodextrin materials can also be reacted with alkylating agents to 
produced an alkylated cyclodextrin. Alkylating groups can be used to 
produce peralkylated cyclodextrin using sufficient reaction conditions 
exhaustively react available hydroxyl groups with the alkylating agent. 
Further, depending on the alkylating agent, the cyclodextrin molecule used 
in the reaction conditions, cyclodextrin substituted at less than all of 
the available hydroxyls can be produced. Typical examples of alkyl groups 
useful in forming the alkylated cyclodextrin include methyl, propyl, 
benzyl, isopropyl, tertiary butyl, allyl, trityl, alkyl-benzyl and other 
common alkyl groups. Such alkyl groups can be made using conventional 
preparatory methods, such as reacting the hydroxyl group under appropriate 
conditions with an alkyl halide, or with an alkylating alkyl sulfate 
reactant. 
Tosyl(4-methylbenzene sulfonyl) mesyl (methane sulfonyl) or other related 
alkyl or aryl sulfonyl forming reagents can be used in manufacturing 
compatibilized cyclodextrin molecules for use in thermoplastic resins. The 
primary --OH groups of the cyclodextrin molecules are more readily reacted 
than the secondary groups. However, the molecule can be substituted on 
virtually any position to form useful compositions. 
Such sulfonyl containing functional groups can be used to derivatize either 
of the secondary hydroxyl groups or the primary hydroxyl group of any of 
the glucose moieties in the cyclodextrin molecule. The reactions can be 
conducted using a sulfonyl chloride reactant that can effectively react 
with either primary or secondary hydroxyl. The sulfonyl chloride is used 
at appropriate mole ratios depending on the number of target hydroxyl 
groups in the molecule requiring substitution. Both symmetrical (per 
substituted compounds with a single sulfonyl moiety) or unsymmetrical (the 
primary and secondary hydroxyls substituted with a mixture of groups 
including sulfonyl derivatives) can be prepared using known reaction 
conditions. Sulfonyl groups can be combined with acyl or alkyl groups 
generically as selected by the experimenter. Lastly, monosubstituted 
cyclodextrin can be made wherein a single glucose moiety in the ring 
contains between one and three sulfonyl substituents. The balance of the 
cyclodextrin molecule remaining unreacted. 
Amino and other azido derivatives of cyclodextrin having pendent 
thermoplastic polymer containing moieties can be used in the sheet, film 
or container of the invention. The sulfonyl derivatized cyclodextrin 
molecule can be used to generate the amino derivative from the sulfonyl 
group substituted cyclodextrin molecule via nucleophilic displacement of 
the sulfonate group by an azide (N.sub.3.sup.-1) ion. The azido 
derivatives are subsequently converted into substituted amino compounds by 
reduction. Large numbers of these azido or amino cyclodextrin derivatives 
have been manufactured. Such derivatives can be manufactured in 
symmetrical substituted amine groups (those derivatives with two or more 
amino or azido groups symmetrically disposed on the cyclodextrin skeleton 
or as a symmetrically substituted amine or azide derivatized cyclodextrin 
molecule. Due to the nucleophilic displacement reaction that produces the 
nitrogen containing groups, the primary hydroxyl group at the 6-carbon 
atom is the most likely site for introduction of a nitrogen containing 
group. Examples of nitrogen containing groups that can be useful in the 
invention include acetylamino groups (-NHAc), alkylamino including 
methylamino, ethylamino, butylamino, isobutylamino, isopropylamino, 
hexylamino, and other alkylamino substituents. The amino or alkylamino 
substituents can further be reactive with other compounds that react with 
the nitrogen atom to further derivatize the amine group. Other possible 
nitrogen containing substituents include dialkylamino such as 
dimethylamino, diethylamino, piperidino, piperizino, quaternary 
substituted alkyl or aryl ammonium chloride substituents, halogen 
derivatives of cyclodextrins can be manufactured as a feed stock for the 
manufacture of a cyclodextrin molecule substituted with a compatibilizing 
derivative. In such compounds the primary or secondary hydroxyl groups are 
substituted with a halogen group such as fluoro, chloro, bromo, iodo or 
other substituents. The most likely position for halogen substitution is 
the primary hydroxyl at the 6-position. 
Hydrocarbyl substituted phosphono or hydrocarbyl substituted phosphato 
groups can be used to introduce compatible derivatives onto the 
cyclodextrin. At the primary hydroxyl, the cyclodextrin molecule can be 
substituted with alkyl phosphato, aryl phosphato groups. The 2, and 3, 
secondary hydroxyls can be branched using an alkyl phosphato group. 
The cyclodextrin molecule can be substituted with heterocyclic nuclei 
including pendent imidazole groups, histidine, imidazole groups, pyridino 
and substituted pyridino groups. 
Cyclodextrin derivatives can be modified with sulfur containing functional 
groups to introduce compatibilizing substituents onto the cyclodextrin. 
Apart from the sulfonyl acylating groups found above, sulfur containing 
groups manufactured based on sulfhydryl chemistry can be used to 
derivatize cyclodextrin. Such sulfur containing groups include methylthio 
(--SMe), propylthio (--SPr), t-butylthio (--S--C(CH.sub.3).sub.3), 
hydroxyethylthio (--S--CH.sub.2 CH.sub.2 OH), imidazolylmethylthio, 
phenylthio, substituted phenylthio, aminoalkylthio and others. Based on 
the ether or thioether chemistry set forth above, cyclodextrin having 
substituents ending with a hydroxyl aldehyde ketone or carboxylic acid 
functionality can be prepared. Such groups include hydroxyethyl, 
3-hydroxypropyl, methyloxylethyl and corresponding oxime isomers, formyl 
methyl and its oxime isomers, carbylmethoxy (--O--CH.sub.2 --CO.sub.2 H), 
carbylmethoxymethyl ester (--O--CH.sub.2 CO.sub.2 --CH.sub.3). 
Cyclodextrin with derivatives formed using silicone chemistry can contain 
compatibilizing functional groups. 
Cyclodextrin derivatives with functional groups containing silicone can be 
prepared. Silicone groups generally refer to groups with a single 
substituted silicon atom or a repeating silicone-oxygen backbone with 
substituent groups. Typically, a significantly proportion of silicone 
atoms in the silicone substituent bear hydrocarbyl (alkyl or aryl) 
substituents. Silicone substituted materials generally have increased 
thermal and oxidative stability and chemical inertness. Further, the 
silicone groups increase resistance to weathering, add dielectric strength 
and improve surface tension. The molecular structure of the silicone group 
can be varied because the silicone group can have a single silicon atom or 
two to twenty silicon atoms in the silicone moiety, can be linear or 
branched, have a large number of repeating silicone-oxygen groups and can 
be further substituted with a variety of functional groups. For the 
purposes of this invention the simple silicone containing substituent 
moieties are preferred including trimethylsilyl, mixed methyl-phenyl silyl 
groups, etc. 
In summary, a large number of possible cyclodextrin substituents are 
feasible, depending on the specific material the cyclodextrin is to be 
dispersed within. However, there are particular substituents which are 
preferred, especially when they are to be dispersed within a starch layer. 
Preferred substituted cyclodextrins include those that are acylated or 
possess trimethyl silyl, hydroxy ethyl or hydroxy propyl substituents. 
Barrier Layers 
FIG. 2 shows a cross section 200 of a preferred composite material typical 
of the invention. This consists of a paperboard layer 240 combined with 
several layers. Starting at the top of the figure is the outer layer 210, 
which consists of an aqueous borne acrylic coating or UV coating that 
contains one or more cyclodextrin species. Under this top layer is a 
printed layer 220 comprising ink, which provides the text and graphics 
used to identify and decorate the carton or other paperboard packaging 
material. The ink layer 220 is deposited on a clay coat 230 which may 
optionally include one or more cyclodextrin species. On the interior 
(product side) of the paperboard material is a diluent layer 250 which 
contains one or more cyclodextrin species. The figure only shows one 
preferred embodiment and is not construed to limit the invention in any 
way. For example, the packaging material could also include one or more 
polymeric layers not shown. A second diluent and cyclodextrin layer could 
be included immediately exterior the paperboard layer 240 to act as a 
barrier to permeants entering from the environment. The invention is 
largely directed to the use of barrier layers which comprise cyclodextrin 
material combined with a diluent in a coating, layer or laminate. The 
barrier layer of the invention can be formed in a variety of ways. The 
barrier layer must comprise a diluent composition in which the 
cyclodextrin is dispersed, dissolved or suspended in an active barrier 
mode. The barrier layer can be formed by coating, coextrusion, lamination, 
spraying, printing, etc. Preferred barrier layers are formed by coating 
from an aqueous solution comprising a diluent and a cyclodextrin. An 
optional preferred barrier layer is formed by coextruding a thermoplastic 
layer comprising a substituted cyclodextrin with the paperboard in a 
coextrusion process to form the barrier layer intimately bonded to the 
cellulosic material. 
Barrier Layer Comprising a Cyclodextrin and a Diluent 
The cyclodextrin materials can be incorporated into a barrier cellulosic 
web by forming the cellulosic web or a similar structure containing a 
cellulosic layer with a layer containing an effective amount of a 
cyclodextrin or substituted cyclodextrin combined with a solid diluent. 
In forming the barrier layers of the invention, coatings can be formed 
either on a film which is later laminated on a film which is later 
laminated onto the cellulosic web or can be coated to form a film on the 
cellulosic web. Such coating processes involve the application of liquid 
to a traveling cellulosic web. Such coating processes commonly use 
machines having an application section and a metering section. Careful 
control of the amount and thickness of the coating obtains optimized 
barrier layers without waste of material. A number of coating machines are 
known such as tension sensitive coaters, for example, coaters using a 
metering rod, tension insensitive coating stations that can maintain coat 
weight even as web tensions vary, brush coating methods, air knife 
coaters, etc. Such coating machines can be used to coat one or both sides 
of a flexible film or one or both sides of a cellulosic web. 
Coating machines described above commonly apply a liquid composition 
containing a film forming material, additives that can help form and 
maintain the coating composition along with the effective amount of the 
cyclodextrin or substituted cyclodextrin material. The film forming 
materials are often called a binder. Such binders exist in the final 
coating as a polymer of high molecular weight. The polymeric layers of the 
invention may also be coextruded together. 
Preferably, the barrier layer comprises, in different diluents: 
______________________________________ 
Coating Type gCD/1000 FT.sup.2 
Range (wt %-of coating) 
______________________________________ 
Starch Coatings 
10-50.sup. 0.5-5 
Cellulose Coatings 10-50.sup. 0.5-5 
Acrylic Coatings 0.05-1.5.sup.1 0.05-0.5 
Extrusion Coatings 0.2-20 .sup. 0.1-3 
______________________________________ 
.sup.1 0.0005 to 0.006 gCD/m.sup.2 
Optionally, the barrier layer can include compounds which fluoresce when 
radiated, particularly when the radiation source comprises X-rays. Such 
compounds are known in the art and include such chemicals as NaCl, NaBr, 
Na.sub.2 SO.sub.4, KCl, KBr, K.sub.2 SO.sub.4, FeCl.sub.2, FeBr.sub.2, 
FeSO.sub.4, and mixtures thereof. 
Polymeric Barrier Layers 
Layers of thermoplastic polymers can be used on either the product or 
exterior side of the cellulosic web. These layers can be used without 
cyclodextrins to help seal the cellulosic web against liquids. They can 
also be used as diluents with cyclodextrins to help form barriers against 
permeant diffusion or migration of volatile thermoplastic polymer 
contaminants, thermal-decomposition products and oligomers. A polymeric 
film on either side of the web can also contain cyclodextrin. 
Because there are many thermoplastic polymers available, it is prudent to 
select a particular polymer according to the particular attributes and 
properties desired. Important properties include tensile strength, 
elongation, stiffness, tear strength and resistance; optical properties 
including haze, transparency; chemical resistance such as water absorption 
and transmission of a variety of permeant materials including water vapor 
and other permeants; electrical properties such as dielectric constant; 
and permanence properties including shrinkage, cracking, weatherability, 
etc. 
Thermoplastic materials can be formed into barrier film using a variety of 
processes including paperboard web extrusion coatings, blown thermoplastic 
extrusion, linear biaxially oriented film extrusion and by casting from 
molten thermoplastic resin, monomer or polymer (aqueous or organic 
solvent) dispersion. These methods are well known manufacturing 
procedures. The characteristics in the polymer thermoplastics that lead to 
successful barrier film formation are as follows. Skilled artisans 
manufacturing thermoplastic polymers have learned to tailor the polymer 
material for thermoplastic processing and particular end use application 
by controlling molecular weight (the melt index has been selected by the 
thermoplastic industry as a measure of molecular weight--melt index is 
inversely proportional to molecular weight, density and crystallinity). 
For thermoplastic extrusion coating polyolefins (polyalpha olefins such as 
(LDPE) low density polyethylene, (LLDPE) linear low density polyethylene, 
(HDPE) high density polyethylene) are the most frequently used 
thermoplastic polymers, although polypropylene, ethylene-vinylacetate 
(EVA), polyethyleneterephthalate (PET or PETG) and 
polybutylene-terephthalate (PBT) are sometimes used to make extrusion 
coatings. Polyolefins typically have a melt index from 0.3 to 20 grams/10 
mins., a density of about 0.910 to about 0.970 grams/cc, and a weight 
average molecular weight (M.sub.w) that can range from about 200,000 to 
500,000. Coextrusion, in which back-to-back layers of two plastic layers 
are coated onto paperboard, makes it possible to adhere nylon, or other 
similarly situated polymers, that by itself will not adhere to paperboard. 
Extrusion coatings are typically 0.30 mil (0.0003 inches). For roll 
coating of aqueous based acrylic, urethane and PVDC, etc. dispersions are 
polymerized to an optimum crystallinity and molecular weight before 
coating. 
A variety of thermoplastic materials are used in making film and sheet 
products. Such materials include 
poly(acrylonitrile-co-butadiene-co-styrene) polymers, acrylic polymers 
such as the polymethylmethacrylate, poly-n-butyl acrylate, 
poly(ethylene-co-acrylic acid), poly(ethylene-co-methacrylate), etc.; 
cellophane, cellulosics including cellulose acetate, cellulose acetate 
propionate, cellulose acetate butyrate and cellulose triacetate, etc.; 
fluoropolymers including polytetrafluoroethylene (TEFLON.RTM.), 
poly(ethylene-co-tetrafluoroethylene) copolymers, (tetrafluoroethylene-co- 
propylene) copolymers, polyvinyl fluoride polymers, etc., polyamides such 
as nylon 6, nylon 6,6, etc.; polycarbonates; polyesters such as 
poly(ethylene-co-terephthalate), poly(ethylene-co-1,4-naphthalene 
decarboxylate), poly(butylene-co-terephthalate); polyamide materials; 
polyethylene materials including low density polyethylene; linear low 
density polyethylene, high density polyethylene, high molecular weight 
high density polyethylene, etc.; polypropylene, biaxially oriented 
polypropylene; polystyrene, biaxially oriented polystyrene; vinyl films 
including polyvinyl chloride, (vinyl chloride-co-vinyl acetate) 
copolymers, polyvinylidene chloride, polyvinyl alcohol, (vinyl 
chloride-co-vinylidene dichloride) copolymers, specialty films including 
polysulfone, polyphenylene sulfide, polyphenylene oxide, liquid crystal 
polyesters, polyether ketones, polyvinylbutyral, etc. 
While a large number of thermoplastic polymers exist and possible serve 
some utility in the claimed invention, particular polymers are preferred. 
Preferred polymers include polyethylene, polypropylene, polyester, 
copolymers comprising vinyl acetate, copolymers comprising vinyl chloride, 
copolymers comprising an acrylic monomer, polymers comprising styrene or 
mixtures thereof. 
The thermoplastic film materials can be laminated to a cellulosic web using 
commonly available typically heat driven laminating techniques. In such 
techniques, the film can be joined to the cellulosic web substrate using 
two common methods. The film can be extruded directly onto the cellulosic 
web and bonded to the web with conventional thermal techniques. In 
extrusion coating processes, plastic pellets containing the cyclodextrin 
derivative are melted at high temperatures (commonly greater than about 
350.degree. C.). The molten plastic is extruded through a narrow slit or 
die. At the same instant this molten material comes into contact with a 
cellulosic web. It is immediately pressed with a very smooth and 
relatively cool chill roll (30-40.degree. C.). Such an operation imparts a 
smooth impervious surface of the plastic as well as forming a strong 
laminating bond to the cellulosic web. Appearance and nature of the 
coating is typically a function of the type of chill roll used and is not 
a characteristic of the plastic material. 
Additionally, the film can be taken from a roll of film and laminated to 
the cellulosic web using heat techniques or through the use of a bonding 
layer which is commonly heat activated. A pre-extruded or precast film can 
be brought into contact with the cellulosic web, heated to a temperature 
greater than its melt point and then is immediately pressed with a smooth 
cool chill roll. Such laminating processes are typically completed using 
well known processes described above. Such a lamination can be improved 
using an adhesive material that can aid in forming a bonded film web 
laminate. Such materials are commonly coated on the film, on the 
cellulosic web prior to heat treatment. 
The cyclodextrin materials can be incorporated into a barrier cellulosic 
web by coating the cellulosic web or a similar structure containing a 
cellulosic layer with a liquid coating composition containing an effective 
amount of a cyclodextrin or substituted cyclodextrin. Such coating 
compositions are typically formed using an aqueous medium. Aqueous media 
are typically formed by combining water with additives and components that 
can form a useful coatable aqueous dispersion. 
In forming the barrier layers of the invention, coatings can be formed 
either on a film which is later laminated on a film which is later 
laminated onto the cellulosic web or can be coated to form a film on the 
cellulosic web. Such coating processes involve the application of liquid 
to a traveling cellulosic web. Such coating processes commonly use 
machines having an application section and a metering section. Careful 
control of the amount and thickness of the coating obtains optimized 
barrier layers without waste of material. A number of coating machines are 
known such as tension sensitive coaters, for example, coaters using a 
metering rod, tension insensitive coating stations that can maintain coat 
weight even as web tensions vary, brush coating methods, air knife 
coaters, etc. Such coating machines can be used to coat one or both sides 
of a flexible film or one or both sides of a cellulosic web. 
Coating machines described above commonly apply a liquid composition 
containing a film forming material, additives that can help form and 
maintain the coating composition along with the effective amount of the 
cyclodextrin or substituted cyclodextrin material. The film forming 
materials are often called a binder. Such binders exist in the final 
coating as a polymer of high molecular weight. Thermoplastic polymers or 
crosslinking polymers can both be used. Such binders are grouped into 
certain overlapping classes including acrylic, vinyl, alkyl, polyester, 
etc. Further, the compositions described above are materials that can be 
used in forming the polymer films also have corresponding materials that 
can be used in the formation of aqueous and solvent based coating 
compositions. Such coating compositions can be made by combining the 
liquid medium with solid materials containing the polymer, the 
cyclodextrin and a variety of useful additives. Preferably, the barrier 
layer includes sufficient cyclodextrin to yield a measurement of 
cyclodextrin per 1000 ft.sup.2 of about 0.2 to 20 g/1000 ft.sup.2 or 0.002 
to 0.22 g/m.sup.2. Optionally, the polymeric barrier layer can include 
compounds which fluoresce when radiated, particularly when the radiation 
source comprises X-rays. Such compounds are known in the art and include 
such chemicals as NaCl, NaBr, Na.sub.2 SO.sub.4, KCl, KBr, K.sub.2 
SO.sub.4, FeCl.sub.2, FeBr.sub.2, FeSO.sub.4, and mixtures thereof. 
Starch and Water Soluble Cellulosic Barrier Layer 
The cyclodextrin materials can be incorporated into a barrier cellulosic 
web by coating the cellulosic web or a similar structure containing a 
cellulosic layer with a liquid coating composition containing an effective 
amount of a cyclodextrin or substituted cyclodextrin combined with a 
starch or water soluble cellulosic diluent. Such coating compositions are 
typically formed using a liquid medium that can act as a carrier for the 
starch and cyclodextrin. Liquid mediums can include an aqueous medium or 
organic solvent media. Aqueous media are typically formed by combining 
water with additives and components that can form a useful coatable 
aqueous dispersion combined with the starch and cyclodextrin. Preferably, 
a barrier layer formed on a web includes sufficient cyclodextrin to yield 
a measurement of from about 10 to 50 grams cyclodextrin per 1000 ft.sup.2 
(about 0.1 to 0.6 g-m.sup.-2). Optionally, the starch or cellulosic 
barrier layer can include compounds which fluoresce when radiated, 
particularly when the radiation source comprises X-rays. Such compounds 
are known in the art and include such chemicals as NaCl, NaBr, Na.sub.2 
SO.sub.4, KCl, KBr, K.sub.2 SO.sub.4, FeCl.sub.2, FeBr.sub.2, FeSO.sub.4, 
and mixtures thereof. 
Packages and Packed Items 
The cellulosic web containing the cyclodextrin or compatible derivatized 
cyclodextrin can be used in a variety of packaging formats to package a 
variety of items. General packaging ideas can be used. For example, the 
items can be packaged entirely in a pouch, bag, etc. Further, the web can 
be used as a paper closure over a rigid plastic container. Such containers 
can have a rectangular, circular, square or other shaped cross-section, a 
flat bottom and an open top. Both the container and a paper or web closure 
can be made of the coated, thermoplastic coated or laminated materials of 
the invention. Further, the coated, thermoplastic coated or laminated 
materials of the invention can be used in the formation of the cellulosic 
portion, blister pack packaging, clam shell type enclosures, tub, tray, 
etc. Products that can be packaged in the methods of the invention include 
coffee, ready to eat cereal, crackers, pasta, cookies, frozen pizza, 
candy, cocoa or other chocolate products, dry mix gravies and soups, snack 
foods (chips, crackers, popcorn, etc.), baked foods, pastries, breads 
etc., dry pet food (cat food, etc.), butter or butter-flavor notes, meat 
products, in particular butter or butter-flavor notes used in the 
manufacture of microwave popcorn in microwaveable paper containers, fruits 
and nuts, etc. 
The above explanation of the nature of the cyclodextrin, the cyclodextrin 
derivatives, thermoplastic films, coatings or manufacturing detail 
regarding the production of film coatings and webs, and the processes of 
cyclodextrin to make compatible derivatives provides a basis for 
understanding technology involving incorporating compatible cyclodextrin 
in a cellulosic web or paperboard structure for barrier purposes. The 
following examples provide a further basis for understanding the invention 
and includes the best mode. 
Thermoplastic Polymer Testing 
The polymer films tested were made according to procedures discussed in 
U.S. Pat. No. 5,603,974, issued Feb. 18, 1997 to Wood et al., which is 
expressly incorporated by reference herein. The test procedures used are 
also described in the same reference. 
Initially, we produced four experimental test films as a model for barrier 
layers. Three of the films contained .beta.-cyclodextrin .beta.CD at 
loading of 1%, 3% and 5% (wt./wt.) while the fourth was a control film 
made from the same batch of resin and additives but without .beta.CD. The 
5% loaded .beta.CD film was tested for complexation of residual organic in 
the test film. The .beta.CD was found to effectively complex residual 
organics in the linear low density polyethylene (LLDPE). 
We have evaluated nine modified .beta.cyclodextrins and a milled 
.beta.-cyclodextrin (particle size 5 to 20 microns). The different 
cyclodextrin modifications were acetylated, an octanyl succinate 
derivative, an ethoxyhexyl glycidyl ether derivative, a quaternary amine 
derivative, a tertiary amine derivative, a carboxymethyl derivative, a 
succinylated, an amphoteric and trimethylsilyl ether derivative. Each 
experimental cyclodextrin (1% loading wt/wt) was mixed with low density 
polyethylene (LLDPE) using a Littleford mixer and then extruded using a 
twin screw Brabender extruder. 
The nine modified cyclodextrin and milled cyclodextrin LLDPE profiles were 
examined under an optical microscope at 50.times. and 200.times. 
magnification. The microscopic examination was used to visually check for 
compatibility between LLDPE resin and cyclodextrin. Of the ten 
cyclodextrin candidates tested, three (acetylated, octanyl succinate and 
trimethylsilyl ether) were found visually to be compatible with the LLDPE 
resin. 
Complexed residual film volatiles were measured using cryotrapping 
procedure to test 5% .beta.CD film sample and three extruded profiles 
containing 1% (wt/wt) acetylated .beta.CD octanyl succinate .beta.CD and 
trimethylsilyl ether. The method consists of three separate steps; the 
first two are carried out simultaneously while the third, an instrumental 
technique for separating and detecting volatile organic compounds, is 
conducted after one and two. In the first step, an inert pure, dry gas is 
used to strip volatiles from the sample. During the gas stripping step, 
the sample is heated at 120.degree. C. The sample is spiked with a 
surrogate (benzene-d.sub.6) immediately prior to the analysis. 
Benzene-d.sub.6 serves as an internal QC surrogate to correct each set of 
test data for recovery. The second step concentrates the volatiles removed 
from the sample by freezing the compounds from the stripping gas in a 
headspace vial immersed in a liquid nitrogen trap. At the end of the 
gas-stripping step, an internal standard (toluene-d.sub.8) is injected 
directly into the headspace vial and the vial is capped immediately. 
Method and system blanks are interspersed with samples and treated in the 
same manner as samples to monitor contamination. The concentrated organic 
components are then separated, identified and quantitated by heated 
headspace high resolution gas chromatography/mass spectrometry (HRGC/MS). 
The results of the residual volatile analyses are presented in the table 
below: 
TABLE 1 
______________________________________ 
PERCENT VOLATILE COMPLEXATION 
Sample Identification 
as Compared to Control 
______________________________________ 
5% .beta.CD Blown Film 
80 
1% Acylated .beta.CD Profile 47 
1% Octanyl Succinate .beta.CD Profile 0 
1% Trimethylsilyl ether Profile 48 
1% .beta.CD Milled Profile 29 
______________________________________ 
In these preliminary screening tests, .beta.CD derivatives were shown to 
effectively complex trace volatile organics inherent in low density 
polyethylene resin used to make experimental film. In 5% .beta.CD loaded 
LLDPE film, approximately 80% of the organic volatiles were complexed. 
However, all .beta.CD films (1% and 5%) had an off-color (light brown) and 
off-odor. The color and odor problem is believed to be the result of 
direct decomposition of the CD or impurity in the CD. Two odor-active 
compounds (2-furaldehyde and 2-furanmethanol) were identified in the blown 
film samples. 
Of the three modified compatible CD candidates (acetylated, octanyl 
succinate and trimethylsilyl ether), the acetylated and trimethylsilyl 
ether CD were shown to effectively complex trace volatile organics 
inherent in the LLDPE resin. One percent loadings of acetylated and 
trimethylsilyl ether (TMSE) .beta.CD showed approximately 50% of the 
residual LPDE organic volatiles were complexed, while the octanyl 
succinate CD did not complex residual LLDPE resin volatiles. Milled 
.beta.CD was found to be less effective (28%) than the acetylated and TMSE 
modified .beta.CD's. 
The 1% TMSE .beta.CD film was slightly better than the 1% acetylated 
.beta.CD film (24% -vs- 26%) for removing aromatic permeants at 72.degree. 
F. adding more modified CD appeared to have no improvement. 
For aromatic permeants at 105.degree. F., both 1% TMSE .beta.CD and 1% 
acetylated .beta.CD are approximately 13% more effective removing aromatic 
permeants than 72EF. The 1% TMSE film was again slightly better than the 
1% film (36% -vs- 31%) for removing aromatic permeants. 
The 1% TMSE film was more effective initially removing aliphatic permeants 
than the 1% acetylated .beta.CD film at 72.degree. F. But for the duration 
of the test, 1% TMSE .beta.CD was worse than the control while 1% 
acetylated .beta.CD removed only 6% of the aliphatic permeants. 
We produced two experimental aqueous coating solutions. One solution 
contained hydroxyethyl .beta.CD (35% by weight) and the other solution 
contained hydroxypropyl .beta.CD (35 by weight). Both solutions contained 
10% of an acrylic emulsion comprising a dispersion of polyacrylic acid 
having a molecular weight of about 150,000 (Polysciences, Inc.) (15% 
solids by weight) as a film forming adhesive. These solutions were used to 
hand-coat test film samples by laminating two LLDPE films together. Two 
different coating techniques were used. The first technique very slightly 
stretched two film samples flat, the coating was then applied using a hand 
roller, and then the films were laminated together while stretched flat. 
The Rev. 1 samples were not stretched during the lamination process. All 
coated samples were finally placed in a vacuum laminating press to remove 
air bubbles between the film sheets. Film coating thicknesses were 
approximately 0.0005 inches. These CD coated films and hydroxylmethyl 
cellulose coated control films were subsequently tested. 
A reduction in aromatic and aliphatic vapors by the hydroxyethyl .beta.CD 
coating is greater in the first several hours of exposure to the vapor and 
then diminishes over the next 20 hours of testing. Higher removal of 
aliphatic vapors than aromatic vapors was achieved by the hydroxyethyl 
.beta.CD coating; this is believed to be a function of the difference in 
their molecular size (i.e., aliphatic compounds are smaller than aromatic 
compounds). Aliphatic permeants were reduced by 46% as compared to the 
control over the 20 hour test period. Reduction of aromatic vapors was 29% 
as compared to the control over the 17 hour test period. 
The Rev. 1 coated hydroxyethyl .beta.CD reduced the aliphatic permeants by 
87% as compared to the control over the 20 hour test period. It is not 
known if the method of coating the film was responsible for the additional 
41% reduction over the other hydroxyethyl .beta.CD coated film. The 
hydroxyethyl .beta.CD coating was slightly better for removing aromatic 
permeants than the hydroxypropyl .beta.CD coating (29% -vs- 20%) at 
72.degree. F. 
Preparation of Cyclodextrin Derivatives 
EXAMPLE I 
An acetylated .beta.-cyclodextrin was obtained that contained 3.4 acetyl 
groups per cyclodextrin on the primary hydroxyl (--OH) group. 
EXAMPLE II 
A .beta.-cyclodextrin was obtained which contained approximately 1.7 
trimethylsilylether substituent per .beta.-cyclodextrin molecule. The 
substitution appeared to be commonly on a primary 6-carbon atom. 
Table 2 gives the identity of each test roll: 
TABLE 2 
______________________________________ 
Extruded Films 
Made with Low Density Polyethylene 
Roll # Sample ID 
______________________________________ 
1 control 
2 1% Ex. I 
3 1% Ex. I 
4 1% Ex. I 
5 1% Ex. I 
6 1% Ex. I 
7 0.5% Ex. I 
8 2% Ex. I 
9 1% Ex. II 
10 1% Ex. II 
11 1% Ex. II 
12 1% Ex. II 
13 0.5% Ex. II 
14 0.5% Ex. II 
15 2% Ex. II 
16 2% Ex. II 
17 2% Ex. II 
______________________________________ 
The results of the testing show that the inclusion of a compatible 
cyclodextrin material in the thermoplastic films of the invention 
substantially improves the barrier properties by reducing transmission 
rate of a variety of fuel vapor permeants. The data showing the 
improvement in transmission rate is shown below in the following data 
tables. 
__________________________________________________________________________ 
Comparison of Transmission Rates in Modified .beta.-Cyclodextrin - LDPE 
Films 
Temperature 72.degree. F. 
Sample Side: Room % RH 
Environment: Room % RH 
Aromatics % Tot. Volatiles % 
Aromatic Improvement Over Total Volatiles Improvement Over 
Sample Identification Transmission Rate* Control Transmission Rate* 
Control 
__________________________________________________________________________ 
Control Film 1.0% CS-001 3.35E-04 0% 3.79E-04 0% 
(Roll #2) 1.0% CS-001 3.18E-04 5% 3.61E-04 5% 
(Roll #3) 1.0% CS-001 2.01E-04 40% 2.55E-04 33% 
(Roll #5) 1.0% CS-001 2.67E-04 20% 3.31E-04 13% 
(Roll #6) 3.51E-04 -5% 3.82E-04 -1% 
__________________________________________________________________________ 
Comparison of Transmission Rates in Modified .beta.-Cyclodextrin - LDPE 
Films 
Temperature 72.degree. F. 
Sample Side: Room % RH 
Environment: Room % RH 
Aromatic Naphtha % 
Sample Identification Transmission Rate* Improvement Over Control 
__________________________________________________________________________ 
Control Film (Roll #1) 7.81E-03 0% 
0.5% CS-001 (Roll #7) 7.67E-03 2% 
1% CS-001 (Roll #5) 7.37E-03 6% 
2% CS-001 (Roll #8) 6.53E-03 16% 
__________________________________________________________________________ 
*gm @ 0.001 in. 
100 in.sup.2 @ 24 hrs. 
Comparison of Transmission Rates in Modified .beta.-Cyclodextrin - LDPE 
Films 
Temperature 72.degree. F. 
Sample Side: Room % RH 
Environment: Room % RH 
Aromatics % Tot. Volatiles % 
Aromatic Improvement Over Total Volatiles Improvement Over 
Sample Identification Transmission Rate* Control Transmission Rate 
Control 
__________________________________________________________________________ 
Control Film (Roll #1) 5.16E-04 0% 5.63E-04 0% 
1.0% CS-001 (Roll #5) 4.01E-04 22% 5.17E-04 8% 
2.0% CS-001 (Roll #8) 2.91E-04 44% 3.08E-04 45% 
__________________________________________________________________________ 
Comparison of Transmission Rates in Modified .beta.-Cyclodextrin - LDPE 
Films 
Temperature 72.degree. F. 
Sample Side: Room % RH 
Environment: Room % RH 
Aromatic Naphtha % 
Sample Identification Transmission Rate* Improvement Over Control 
__________________________________________________________________________ 
Control Film (Roll #1) 7.81E-03 0% 
0.5% CS-001 (Roll #7) 7.67E-03 2% 
1% CS-001 (Roll #5) 7.37E-03 6% 
2% CS-001 (Roll #8) 6.53E-03 16% 
__________________________________________________________________________ 
*gm @ 0.001 in. 
100 in.sup.2 @ 24 hrs. 
Comparison of Transmission Rates in Modified .beta.-Cyclodextrin - LLDPE 
Films 
Temperature 72.degree. F. 
Sample Side: 0.25 Aw 
Environment: 60% RH 
Aromatics % T. Volatiles % 
Aromatic Improvement Over Total Volatiles Improvement Over 
Sample Identification Transmission Rate* Control Transmission Rate* 
Control 
__________________________________________________________________________ 
Control Film (Roll #1) 3.76E-04 0% 3.75E-04 0% 
0.5% CS-001 (Roll #7) 2.42E-04 36% 2.41E-04 36% 
1% CS-001 (Roll #5) 3.39E-04 10% 3.38E-04 10% 
2% CS-001 (Roll #8) 2.48E-04 34% 2.47E-04 34% 
__________________________________________________________________________ 
Comparison of Transmission Rates in Modified .beta.-Cyclodextrin - LDPE 
Films 
Temperature 105.degree. F. 
Sample Side: Room % RH 
Environment: Room % RH 
Aromatics % T. Volatiles % 
Aromatic Improvement Over Total Volatiles Improvement Over 
Sample Identification Transmission Rate* Control Transmission Rate* 
Control 
__________________________________________________________________________ 
Control Film (Roll #1) 1.03E-03 0% 1.13E-03 0% 
1% CS-001 (Roll #2) 5.49E-04 47% 5.79E-04 49% 
1% CS-001 (Roll #3) 4.74E-04 54% 5.00E-04 56% 
1% CS-001 (Roll #4) 6.41E-04 38% 6.83E-04 40% 
1% CS-001 (Roll #5) 5.22E-04 49% 5.54E-04 51% 
1% CS-001 (Roll #6) 4.13E-04 60% 4.39E-04 61% 
2% CS-001 (Roll #8) 5.95E-04 42% 6.18E-04 45% 
1% TMSE (Roll #12) 8.32E-04 19% 8.93E-04 21% 
__________________________________________________________________________ 
*gm @ 0.001 in. 
100 in.sup.2 @ 24 hrs. 
Comparison of Transmission Rates in Modified .beta.-Cyclodextrin - LDPE 
Films 
Temperature 105.degree. F. 
Sample Side: Room % RH 
Environment: Room % RH 
Aromatics % T. Volatiles % 
Aromatic Improvement Over total Volatiles Improvement Over 
Sample Identification Transmission Rate* Control Transmission Rate* 
Control 
__________________________________________________________________________ 
Control Film (Roll #1) 4.34E-04 0% 4.67E-04 0% 
0.5% CS-001 (Roll #7) 4.03E-04 7% 4.41E-04 6% 
1.0% CS-001 (Roll #5) 5.00E-04 -15% 5.33E-04 -14% 
2.0% CS-001 (Roll #8) 3.96E-04 9% 3.94E-04 16% 
__________________________________________________________________________ 
Comparison of Transmission Rates in Modified .beta.-Cyclodextrin - LDPE 
Films 
Temperature 72.degree. F. 
Sample Side: Room % RH 
Environment: Room % RH 
Aromatics % T. Volatiles % 
Aromatic Improvement Over Total Volatiles Improvement Over 
Sample Identification Transmission Rate* Control Transmission Rate* 
Control 
__________________________________________________________________________ 
Control Film 3.09E-04 0% 3.45E-04 0% 
0.5% TMSE (Roll #13) 2.50E-04 19% 2.96E-04 14% 
0.5% TMSE (Roll #14) 2.37E-04 23% 2.67E-04 33% 
1% TMSE (Roll #9) 2.67E-04 14% 3.05E-04 12% 
1% TMSE (Roll #10) 4.85E-04 -57% 5.27E-04 -53% 
1% TMSE (Roll #11) 2.58E-04 17% 2.92E-04 15% 
1% TMSE (Roll #12) 2.15E-04 31% 2.55E-04 26% 
2% TMSE (Roll #15) 2.54E-04 18% 3.04E-04 12% 
2% TMSE (Roll #16) 2.79E-04 10% 3.21E-04 7% 
2% TMSE (Roll #17) 2.81E-04 9% 3.24E-04 6% 
__________________________________________________________________________ 
*gm @ 0.001 in. 
100 in.sup.2 @ 24 hrs. 
Comparison of Transmission Rates in Modified .beta.-Cyclodextrin - LDPE 
Films 
Temperature 72.degree. F. 
Sample Side: Room % RH 
Environment: Room % RH 
Aromatic Naphtha % 
Sample Identification Transmission Rate* Improvement Over Control 
__________________________________________________________________________ 
Control Film (Roll #1) 9.43E-03 0% 
1% TMSE (Roll #12) 1.16E-02 -23% 
2% TMSE (Roll #15) 1.56E-02 -65% 
__________________________________________________________________________ 
Comparison of Transmission Rates in Modified .beta.-Cyclodextrin - LDPE 
Films 
Temperature 72.degree. F. 
Sample Side: Room % RH 
Environment: Room % RH 
Aromatics % T. Volatiles % 
Aromatic Improvement Over Total Volatiles Improvement Over 
Sample Identification Transmission Rate* Control Transmission Rate* 
Control 
__________________________________________________________________________ 
Control Film (Roll #1) 8.36E-04 0% 9.05E-04 0% 
0.5% TMSE (Roll #14) 6.77E-04 19% 7.25E-04 20% 
2% TMSE (Roll #15) 6.36E-04 24% 6.81E-04 25% 
__________________________________________________________________________ 
*gm @ 0.001 in. 
100 in.sup.2 @ 24 hrs. 
Comparison of Transmission Rates in Modified .beta.-Cyclodextrin - LDPE 
Films 
Temperature 72.degree. F. 
Sample Side: 0.25 Aw 
Environment: 60% RH 
Aromatics % T. Volatiles % 
Aromatic Improvement Over Total Volatiles Improvement Over 
Sample Identification Transmission Rate* Control Transmission Rate* 
Control 
__________________________________________________________________________ 
Pvdc Control 6.81E-05 0% 1.05E-04 0% 
PVdC w/10% HP B-CyD 1.45E-05 79% 2.39E-05 77% 
PVdC w/20% HP B-CyD 9.71E-05 -42% 1.12E-04 -7% 
__________________________________________________________________________ 
Comparison of Transmission Rates in Modified .beta.-Cyclodextrin - LDPE 
Films 
Temperature 72.degree. F. 
Sample Side: Room % RH 
Environment: Room % RH 
Aromatics % T. Volatiles % 
Aromatic Improvement Over Total Volatiles Improvement Over 
Sample Identification Transmission Rate* Control Transmission Rate* 
Control 
__________________________________________________________________________ 
Control Acrylic 2.07E-06 0% 2.10E-05 0% 
5% HP B-CyD/Acrylic 1.50E-06 27% 2.07E-05 1% 
10% HP B-CyD/Acrylic 4.13E-06 -100% 4.30E-05 -105% 
__________________________________________________________________________ 
*gm @ 0.001 in. 
100 in.sup.2 @ 24 hrs. 
Modified Cellulose Polymeric Testing 
Substrate 
A finished paperboard carton combines binders, inks, overprint varnishes 
and plastics as part of a multi-layer structure. The carton finishing 
materials are sources of odorous volatile substances that can adversely 
affect flavor/aroma qualities of packaged food products. Odorous 
substances are typically substances containing functional groups such as 
aldehydes, esters, acetates and also those with unsaturated groups. 
Paperboard Sample Preparation 
Comparative laboratory analytical and sensory testing was conducted on 
printed recycled paperboard carton samples overcoated with water-based 
acrylic and cellulose coatings. Table 3 summarizes the carton coatings. 
Sample variables include: overprint acrylic coating, with and without 
cyclodextrin treatment, and cellulose coating with and without 
cyclodextrin. 
TABLE 3 
__________________________________________________________________________ 
Carton Coating Variables 
Test Variables Coating Weight.sup.a 
Sample 
Overprint Acrylic Cellulose 
Cyclodextrin Coating 
Weight.sup.a 
Sample Description 
Identification 
Acrylic Coating 
Cellulose Coating 
Coating g/M.sup.2 
Coating g/M.sup.2 
Acrylic mg/M.sup.2 
Cellulose mg/M.sup. 
2 
__________________________________________________________________________ 
Printed Paperboard Control No Cyclodextrin No Cyclodextrin 7.3 0.043 NA 
NA 
Printed Paperboard Test Cyclodextrin.sup.b Cyclodextrin 7.3 0.300 25 
__________________________________________________________________________ 
215 
.sup.a. Dry Weight Basis. 
.sup.b. Blend containing 70% alpha and 30% gamma cyclodextrin. 
.sup.c. Blend containing 50% alpha and 50% gamma cyclodextrin 
Cellulose Coating Solution 
Two cellulosic coating solutions were prepared: a 0.5% cellulose solution 
and a 0.5% cellulose solution with 1.5% cyclodextrin (50% alpha and 50% 
gamma cyclodextrin) the cellulose acting as a diluent. The 0.5% cellulose 
solution was prepared by diluting 1.8 g of hydroxypropyl methyl cellulose 
(Hercules MP-943W) with 358 g of deionized water to produce 360 g of a 
0.5% cellulose solution. The cyclodextrin containing cellulose solution 
was prepared diluting 1.8 g of hydroxypropyl methyl cellulose with 2.7 g 
of alpha cyclodextrin (Wacker Biochem Corporation) and 2.7 g of gamma 
cyclodextrin (Wacker Biochem Corporation) with 352 g of deionized water to 
produce 360 g of a 0.5% cellulose solution. 
Acrylic Coating Solution 
Two acrylic solutions were prepared. A control solution of a waterbased 
acrylic overprint coating (Coatings and Adhesives Corporation, 1245C) used 
"as received." The second 1245C acrylic coating solution contained 0.13% 
cyclodextrin (70% alpha and 30% gamma cyclodextrin). The latter was 
prepared by mixing 0.326 g of alpha cyclodextrin and 0.140 g of gamma 
cyclodextrin with 359.5 g of 1245C coating. 
Coating Process 
All paperboard coatings were performed on a clean, smooth glass plate 12 
inches wide and 24 inches long. A 12-inch #2.5 drawdown bar with a 
0.25-inch diameter from Industry Tech of Oldsmar, Florida, was used to 
apply the acrylic and cellulose coatings. For each board, an excess of the 
cellulose or acrylic coating solution was applied to a 
16".times.4".times.0.04" sheet of clean, rigid PVC at one end of the 
paperboard in a pool 11 to 12 inches long. 
The cellulose coating solution was drawn across the backside (unprinted 
side) of the paperboard at a constant speed, using the drawdown rod at the 
rate of 1.1 to 1.4 seconds to complete each board. Coated boards were 
allowed to dry at ambient conditions for two hours. 
Following the cellulose coating, the paperboard carton samples were coated 
with a water-based acrylic coating. The acrylic coatings were applied to 
the printed cartonboard surface in an identical fashion as the cellulose 
coating. Coated boards were allowed to dry at ambient conditions for one 
hour and then the control and test samples were separately wrapped in 
aluminum foil until the samples were compared analytically or by sensory 
analysis. 
Sensory Test Procedures 
Overview: The inherent odor-producing volatiles from a finished paperboard 
are emitted into the jar's headspace during confinement, and the odor 
intensity is rated by a panel of judges. Panelists smell the headspace of 
each jar and rate the intensity of cartonboard off-odors using a category 
scale with 0=no off-odors to 8=very strong off-odors. 
Materials: 16 oz Mason jars with lids, glass vials 12 mm.times.75 mm 
containing 3 ml DI water, 4".times.4" pieces of foil, controlled 
environment maintained at 100.degree. F. (38.degree. C.) and 4".times.10" 
paperboard samples. 
Procedure: A sample (4".times.10") was cut from each carton. Control and 
test carton samples were cut from the same carton location. Each sample 
was carefully rolled on its narrow side while inserting small glass 
capillary tubes to separate the concentric coils. The cartonboard sample 
was placed into a 16-oz. Mason jar, and then the vial of water was added. 
A 4".times.4" piece of aluminum foil was used to cover the mouth of the 
jar, and then the lid was screwed onto the jar over the foil. Twenty jars 
of test samples and twenty corresponding control samples were prepared for 
the odor panel. The sample jars were placed into a controlled environment 
maintained at 100.degree. F. (38.degree. C.) for 25 hours. Following 25 
hours at 100.degree. F. temperature, the samples were removed from the 
controlled environment and held at ambient for 16 hours before sensory 
evaluation. Each jar was identified with a three-digit code label. Equal 
numbers of control and test cartonboard combinations of AB and BA were 
presented to the panel. Each panel judge was presented two coded samples. 
The panelist opens the left jar and smells the headspace; then the right 
jar and smells the headspace. Judges rate cartonboard off-odors using the 
following category scale: 
0=no off-odor 
1=just detectable 
2=very slight 
3=slight 
4=slight-moderate 
5=moderate 
6=moderate-strong 
7=strong 
8=very strong off-odor. 
Results: ANOVA was used to determine whether there was a statistical 
difference between the off-odor intensity scores of the control and test 
samples. The least significant difference test (LSD) was used to compare 
odor intensity mean scores of the control and test. The mean scores were 
significantly different from each other (.alpha.=0.05). Odor intensity 
test results are provided below in Table 4. 
TABLE 4 
______________________________________ 
Jar Odor Sensory Results 
Jar Odor Sensory Test 
Sample Identification 
Mean Score 
______________________________________ 
Control 5.5.sup.a 
Test 4.8.sup.b 
______________________________________ 
ab = significantly different at .alpha. = 0.05 
Dynamic Headspace High Resolution Gas Chromatography/Mass Spectrometry 
Overview: The inherent volatile compounds emitted from the cartonboard 
samples into the jar's headspace during confinement were qualitatively and 
quantitatively determined by dynamic headspace trapping of the cartonboard 
volatiles and subsequent high resolution gas chromatography/mass 
spectrometry (GC/MS) analysis. 
Materials: 250 ml I-Chem bottle with TEFLON.RTM. lined lids, glass vials 12 
mm.times.75 mm containing 3 ml DI water, controlled environment maintained 
at 100.degree. F. (38.degree. C.), and two 3 1/2"10" paperboard samples. 
Procedure: Two 3 1/2".times.10" cartonboard strips were cut from the 
carton. Control and test carton samples were cut from the same carton 
location. The paperboard sample was rolled on its narrow side while 
inserting small glass capillary tubes to separate the concentric coils. 
The paperboard roll was placed into a 250 ml I-Chem bottle, and then a 
vial of water was placed in the interior of the coiled paperboard. Sample 
bottles were placed into a controlled environment maintained at 
100.degree. F. (38.degree. C.) for 24 hours. After 25 hours at 100.degree. 
F., the samples were removed from the controlled environment and held at 
ambient for three holding times: 1, 24 and 120 hours before analysis. At 
each ambient sample hold time, a bottle was transferred to a purge and 
trap sampler (Hewlett Packard model 19395A) interfaced via injection port 
to a Hewlett Packard 5890 gas chromatograph. The GC capillary column was 
interfaced directly to a Hewlett Packard model 5970 mass spectrometer 
(MS). The purge and trap sampler was modified to hold the larger format 
I-Chem sample bottle. Before analysis, two internal standards 
(1,4-difluorobenzene and chlorobenzene-d5) and two surrogate standards 
(bromochloromethane and naphthalene-d10) were injected through the septa 
into the sample bottle. The MS was operated in a mass range from 35 to 260 
amu and with an ionization voltage of 70 ev. The samples were purged for 
15 minutes at a flow rate of 30 ml/min. and the effluent trapped onto a 
Tenax column. Following the purge cycle, the Tenax trap was rapidly 
heated, transferring the trapped compounds to the gas chromatograph 
capillary column where the compounds are separated prior to entering the 
mass spectrometer. Sample analyte spectra were individually reviewed and 
compared to reference spectra. 
Analyze Results: Test sample analyte identification was made by GC 
retention time (min) and by comparing analyte spectra to standard 
reference materials spectra. Quantitation of the test analytes was based 
upon each analyte's response factor to an internal standard. The earliest 
retention time analytes up to 19 minutes are quantitated against 
1,4-difluorobenzene (an internal standard), and analytes from 19 minutes 
to 30 minutes are quantitated against chlorobenzene-d5 internal standard. 
Test results are provided in Table 5. 
The test data show both a sensory odor intensity and analytical analyte 
reduction in the cartonboard coated with cellulose and acrylic coatings 
containing cyclodextrin, compared t o cartonboard coated with cellulose 
and acrylic coatings without cyclodextrin. 
TABLE 5 
__________________________________________________________________________ 
Analysis Results of Jar Headspace Volatiles from Cartonboard Samples 
Sample Identification: Hold 
Time @ Room Temperature 
Olfactory Control.sup.1 
Test.sup.2 
Control.sup.3 
Test.sup.4 
Control.sup.5 
Test.sup.6 
Threshold 
Retention 
1 hour 
1 hour 
% 24 hours 
24 hours 
% 120 hours 
120 hours 
% 
Compound (ppb) Time (Min.) ug/g ug/g Reduction ug/g ug/g Reduction ug/g 
ug/g Reduction 
__________________________________________________________________________ 
Acetone -- 3.88 1.03 0.747 
27% 1.29 0.737 
43% 2.02 1.17 42% 
Methyl Acetate 6,170 4.78 0.024 0.010 58% 0.027 0.013 52% 0.053 0.027 
49% 
1-Hexene -- 6.65 0.006 0.005 17% 0.011 0.009 18% 0.013 0.009 31% 
Butanal 8.9 
7.19 0.054 
0.044 19% 0.071 
0.052 27% 0.095 
0.043 55% 
Pentanal 6.0 
11.6 0.290 
0.231 20% 0.349 
0.295 15% 0.441 
0.349 21% 
Hexanal 13.8 
15.34 0.748 
0.598 20% 0.785 
0.681 13% 0.946 
0.844 11% 
Xylene (mixed 
m, 324 17.53 
0.015 0.007 53% 
0.01 0.007 30% 
0.013 0.007 46% 
p) 
2-Heptanone 141 18.06 0.011 0.008 27% 0.012 0.008 33% 0.013 0.010 23% 
Styrene 140 
18.20 0.064 
0.027 58% 0.044 
0.034 23% 0.055 
0.033 40% 
Heptanal 4.7 
18.58 0.042 
0.029 31% 0.048 
0.034 29% 0.041 
0.036 12% 
Isopropylbenzen 
e 23.9 19.32 
0.033 0.016 52% 
0.021 0.016 24% 
0.030 0.015 50% 
Octanal 1.3 21.80 0.023 0.019 27% 0.022 0.017 23% 
__________________________________________________________________________ 
analyte concentration is in ug/g = Parts per million (ppm). 
% Reduction = Based on the analyte concentration reduction in the test 
sample relative to control. 
Olfactory Threshold (ppb) = Olfactory odor detection threshold in air ppb 
(volume). Standardized Human Olfactory Thresholds. M. Devos, F. Patte, J. 
Rouault, P. Laffort and L. J. VanGemert 
.sup.1. Values are the average of three samples. 
.sup.2. Values are the average of three samples. 
.sup.3. Values are from a single sample. 
.sup.4. Values are the average of three samples. 
.sup.5. Values are the average of two samples. 
.sup.6. Values are the average of two sample 
The sensory and analytical data set forth above show a substantial 
improvement in barrier or trapping properties of a product comprising the 
layers containing cyclodextrin. The barrier or trapping layer is made 
using a modified cellulose diluent. This material is a common material but 
can be replaced with starch or other organic or inorganic diluent without 
a significant difference in barrier or trapping properties. Table 4 
displaying jar odor sensory results establishes a statistically 
significantly different result in sensory responses of a human test panel 
to the degree odor intensity. These data show that perceptive individuals 
can detect a stronger off-odor in cartonboard without a barrier trap 
compared to cartonboard with a barrier trap of the invention. 
In Table 5, instrumental analytical data is summarized showing that this 
sensory result is based on a demonstrable and measurable reduction in the 
concentration of known odor components because of the barrier or trapping 
properties of the invention. Known odor components such as ketone 
compounds, unsaturated compounds, aldehyde compounds and aromatic 
compounds are all substantially reduced by the contaminant barrier or trap 
materials. These data show the contaminant barrier traps are highly 
efficient in reducing the amount of a variety of these organic compounds 
as they pass through the cellulosic web. 
The above specification cellulosic web laminates and coated cellulosic web 
laminates and test data provide a basis for understanding the technical 
aspects of the invention. Since the invention can be made with a variety 
of embodiments, the invention resides in the claims hereinafter appended.