Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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GUM BASES, CHEWING GUMS BASED THEREUPON, AND METHODS FOR MAKING
THE SAME
INVENTORS: XIAOHU XIA, KEN LIN, PHIL SHEPHERD, MICHAEL HAAS, TAWFIK SHARKASI,
[0001] (Blank)
BACKGROUND OF THE INVENTION
[0002]The present invention relates to gum bases and chewing gums. More
specifically,
this invention relates to improved chewing gum bases and chewing gums with
enhanced
removability, as well as methods of manufacturing the gum bases.
[0003]The precursor's to today's chewing gum compositions were developed in
the
nineteenth century. Today's version is enjoyed daily by millions of people
worldwide.
[0004]When chewing gum is chewed, water soluble components, such as sugars and
sugar alcohols are released with varying degrees of speed within the mouth,
leaving a
water insoluble chewing gum cud. After some amount of time, typically after
the majority
of the water soluble components have been released therefrom, the cud may be
disposed of by the user. Although typically not problematic when disposed of
properly,
e.g., when wrapped in a substrate such as the original wrapper, or disposed of
in a
proper receptacle, improper disposal of chewing gum cuds can result in
adhesion of
cuds to environmental surfaces such as sidewalks, walls, flooring, clothing
and furniture.
[0005]Conventional elastomers and gum bases used in commercial chewing gum
products behave as viscous liquids which provide flow and elasticity
characteristics
which contribute to their desirable chewing properties. However, when the
chewed cuds
formed from such conventional chewing gum products become undesirably adhered
to
rough environmental surfaces such as concrete, over time, the elastomeric
components
flow into the pores, cracks and crevices of such surfaces. The process may be
exacerbated by exposure to pressure (for example through foot traffic) and
temperature
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cycling. If not removed promptly, adhered gum cuds can be extremely difficult
to remove
from these environmental surfaces.
[0006]Thus there is a need for a gum base and chewing gum comprising the same
that
exhibits the desired characteristics for consumer acceptability, while also
producing a
cud which is easily removable from surfaces onto which it may have become
adhered.
SUMMARY OF THE INVENTION
[0007] A gum base comprises microparticles containing at least one crosslinked
polymer.
It has been found that such gum bases exhibit desirable chewing properties
similar to
conventional gum bases. Cuds formed by chewing gum bases containing
crosslinked
polymer microparticles are easily removable from environmental surfaces such
as
concrete, fabrics and flooring materials.
DESCRIPTION OF THE DRAWINGS
[0008]These and other features, aspects and advantages of the present
invention will
become better understood when the following detailed description is read with
reference
to the accompanying drawings wherein:
[0009] FIG. 1 is a graphical depiction of the shear storage modulus at 37 C of
a gum cud
prepared from a comparative chewing gum formulation and of a gum cud prepared
from
a gum base of the present invention; and
[0010] FIG. 2 is a graphical depiction of the shear loss modulus at 37 C of a
gum cud
prepared from one embodiment of a chewing gum formulation and of a gum cud
prepared from a gum base of the present invention as described herein.
[0011] FIG 3 is a drawing of a polymer composite microparticle of the present
invention.
[0012]FIG 4 is a schematic depiction of a process for preparing hollow shell
microparticles of the present invention.
[0013] FIG 5 is a photomicrograph of a hollow shell microparticle of the type
claimed in
some embodiments of the present invention.
[0014] FIG 6 is a cutaway drawing of a core-shell microparticle of the present
invention.
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DESCRIPTION OF THE INVENTION
[0015]The present invention relates to gum bases which incorporate crosslinked
polymer microparticles of a type previously known and used to form pressure
sensitive
adhesives used in a variety of applications. It has now been surprisingly
discovered that
such crosslinked polymer microparticles can be used to prepare gum bases
having a
variety of desirable attributes.
[0016] In some embodiments, the crosslinked polymeric microparticles may be
nonuniform. By non-uniform, it is meant that the microparticles have a
structure other
than a chemically and physically homogenous particle. In some embodiments, the
non-
uniform crosslinked polymeric microparticles may be in the form of a polymer
composite
of two or more different crosslinked polymeric microparticle components
covalently
bonded together at their contacting surfaces. The microparticle components are
themselves microparticles, the term microparticle components being used to
distinguish
these from microparticles in finished form which are used in other embodiments
of the
present invention. By different, it is meant that the microparticle components
come from
different populations of microparticles which differ in some property such as
average
particle size, polymeric composition, degree of crosslinking or other physical
or chemical
property or properties such that, if they were used separately, they would
convey
different properties to a chewing gum product made from them. By covalently
bonding
two or more different particle components together and incorporating the
resulting
polymer composite into a chewing gum product, the texture and chewing
properties can
be carefully adjusted to produce a product with the desired attributes.
[0017] In some embodiments, the non-uniform microparticle will be in the form
of a
hollow shell. By hollow shell, it is meant that the roughly spherical
microparticle is a shell
that substantially or completely surrounds a void within the shell. Such voids
may
constitute 25 to 75% of the volume of the hollow shell microparticle. Such
hollow shell
microparticles will have different textural properties such as a softer
texture and greater
elasticity as compared to a solid microparticle of the same size and polymeric
composition.
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[0018] In some embodiments, the non-uniform microparticles will be in the form
of a
core-shell or filled shell. Such embodiments are similar to that of the hollow
shell except
that, instead of a void, the shell substantially or completely surrounds a
solid or liquid
core. The core may be a liquid such as water, vegetable oil, glycerin,
hydrogels or an
aqueous flavor emulsion or combinations thereof. Alternatively, the core may
be a solid
such as a sugar or sugar alcohol granule or particle, a wax, a solid fat, a
polymer having
a different polymeric composition from the shell.
[0019]The crosslinked polymer may have a glass transition temperature of less
than
about 30 C, or less than about 10 C or even less than about 0 C. In these,
and/or other,
embodiments, the crosslinked polymer may have a complex modulus (G*) at 25 C
of
less than about 109 dyne/cm2, or less than about 107 dyne/cm2. In yet other
embodiments, the crosslinked polymer may desirably have a complex modulus (G*)
of
greater than about 104 dyne/cm2, or greater than about 105 dyne/cm2.
[0020]The microparticles may have a largest dimension of at least 0.01 microns
or at
least 0.1 microns or of at least 0.5 microns or at least 10 microns. The
microparticles
may have a largest dimension of less than about 1000 microns, or less than
about 500
microns or less than about 100 microns.
[0021] In some embodiments, the microparticles may comprise a food grade
polymer
and may or may not be plasticized. In these, and other, embodiments, the
polymer may
comprise a polyacrylate, a polyurethane, or copolymers of these. If a
polyacrylate is
desired, the polyacrylate may be prepared from at least one acrylate monomer
comprising isooctyl acrylate, 4-methyl-2-pentyl-acrylate, 2-methylbutyl
acrylate, isoamyl
acrylate, sec-butyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate,
isodecyl methacrylate,
isononyl acrylate, isodecyl acrylate or combinations (i.e. copolymers) of
these. In certain
embodiments, when a polyacrylate is desirably used, it may be prepared from
isoctyl
acrylate, 2-ethylhexyl acrylate, n-butyl acrylate, or copolymers of these.
[0022]The microparticles may comprise the entirety of the gum base or may
comprise
from about 0.1 weight percent (wt%) to about 99 wt%, or from about 1 wt% to
about 70
wt% or from about 5 wt% to about 40 wt%, based upon the total weight of the
gum base.
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[0023]Although the present gum bases are expected to exhibit enhanced
removability, in
some embodiments, the gum bases may further comprise at least one removability
enhancing component. The removability enhancing component may comprise an
amphiphilic polymer, a low tack polymer, a polymer comprising hydrolysable
units, an
ester or ether of a polymer comprising hydrolysable units, block copolymers or
combinations of these.
[0024]The inventive gum base may further comprise at least one elastomer,
elastomer
solvent, softener, plastic resin, filler, emulsifier, or combinations of
these. In certain
embodiments, the gum base further comprises a filler, e.g., calcium carbonate,
talc,
amorphous silica, or combinations of these, in amounts of from about 0 wt% to
about 5
wt%, based upon the total weight of the gum base.
[0025] In another aspect, a chewing gum is provided comprising a first gum
base
comprising a plurality of microparticles comprising at least one crosslinked
polymer. The
first gum base may comprise from about 1 wt% to about 98 wt% of the chewing
gum, or
from about 10 wt% to about 50 wt%, or from about 20 wt% to about 35 wt% of the
chewing gum, based upon the total weight of the gum.
[0026]The chewing gum may comprise the first gum base as the sole gum base
component, or, in other embodiments, may comprise a second, conventional gum
base.
In such embodiments, the first gum base may comprise from about 0.1 wt% to
about 30
wt% of the chewing gum, based upon the total weight of the gum.
[0027] In addition to any amounts thereof in the gum base, the chewing gum may
include
at least one removability enhancing component. In some embodiments, the
removability
enhancing component included in the chewing gum comprises an emulsifier, that
may be
encapsulated or spray dried, if desired.
[0028] In another aspect, the use of crosslinked polymeric microspheres as a
gum base
is provided.
[0029]And in yet another embodiment, methods for manufacturing a gum base are
further provided and comprise the steps of adding an aqueous slurry of
crosslinked
polymeric microparticles to a mixer, adding at least one of an elastomer, an
elastomer
solvent, a softener, a resin, a filler and/or an emulsifier to the mixer,
mixing the
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components at elevated temperature for a time sufficient to evaporate at least
a majority
of the water, and discharging the mixture from the mixer.
[0030]Unless defined otherwise, technical and scientific terms used herein
have the
same meaning as is commonly understood by one of ordinary skill in the art to
which this
invention belongs. The terms "first", "second", and the like, as used herein
do not denote
any order, quantity, or importance, but rather are used to distinguish one
element from
another. Also, the terms "a" and "an" do not denote a limitation of quantity,
but rather
denote the presence of at least one of the referenced item, and the terms
"front", "back",
"bottom", and/or "top", unless otherwise noted, are merely used for
convenience of
description, and are not intended to limit what is being described to any one
position or
spatial orientation.
[0031]Reference is occasionally made herein to a largest dimension of the
microparticles disclosed herein. It is to be understood that when particular
ranges are
indicated as advantageous or desired for these measurements, or that a
particular shape
of the microparticles may be desirable, that these ranges/shapes may be based
upon the
measurement or observation of from about 1 to about 10 microparticles, and
although it
may generally be assumed that a majority of the microparticles may thus
exhibit the
observed shape or be within the range of largest dimension provided, that the
ranges are
not meant to, and do not, imply that 100% of the population, or 90%, or 80%,
or 70%, or
even 50% of the microparticles need to exhibit a shape or possess a largest
dimension
within this range. All that is required is that a sufficient number of the
microparticles
exhibit a dimension within the desired range and/or the desired shape so that
at least a
portion of the desired properties of the microparticles, and thus the gum base
and
chewing gum, are provided.
[0032] If ranges are disclosed, the endpoints of all ranges directed to the
same
component or property are inclusive and independently combinable (e.g., ranges
of "up
to about 25 wt%, or, more specifically, about 5 wt% to about 20 wt%," is
inclusive of the
endpoints and all intermediate values of the ranges of "about 5 wt% to about
25 wt%,"
etc.). The modifier "about" used in connection with a quantity is inclusive of
the stated
value and has the meaning dictated by the context (e.g., includes the degree
of error
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associated with measurement of the particular quantity). Further, unless
otherwise
stated, percents listed herein are weight percents (wt%) and are based upon
the total
weight of the gum base or chewing gum, as the case may be.
[0033]The present invention provides gum bases and chewing gums, as well as
methods of manufacturing the gum bases. More specifically, the gum bases
provided
herein comprise microparticles further comprising one or more crosslinked
polymer(s).
The polymeric microparticles may render a gum cud comprising the gum base more
easily removable from surfaces to which it may have become adhered than gum
cuds
comprising conventional gum bases. Advantageously, the present gum bases also
have
chew properties consistent with those of conventional gum bases. That is, the
gum base
comprising the polymeric microparticles is elastic yet deformable, more
cohesive than
adhesive, and readily recombines if torn apart. As a result, a chewing gum
comprising
the gum base is expected to enjoy a high consumer-acceptability.
[0034] Polymeric microparticles suitable for use in the chewing gum base
described
herein should be sufficiently pliable at typical mouth temperatures (e.g., 35-
40 C) to give
good chewing properties.
Further, the polymeric microparticles will desirably be
essentially without taste and have an ability to incorporate flavor materials
which provide
a consumer-acceptable flavor sensation. Typically, the microparticles will
have sufficient
cohesion such that a chewing gum comprising them retains cohesion during the
chewing
process and forms a discrete gum cud.
[0035]The polymer(s) used will desirably be crosslinked, either before, during
or after
the formation thereof into microparticles. As used herein, the term
"crosslinked" means
the linking of the chains of a polymer to one another so that the polymer, as
a network,
becomes stronger and more resistant to being dissolved. In at least some
embodiments
all, or most (i.e., greater than 50% of the polymers, based upon the total
number
thereof), of the polymers within a microparticle will be crosslinked.
In other
embodiments, the crosslinking may be incomplete and a minority (i.e., less
than 50% of
the polymers, based upon the total number of polymers) of the polymers within
the
microparticle will be crosslinked. However, as long as the crosslinking is
sufficient to
provide at least a portion of the properties described herein to the gum base
and/or
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chewing gum, the amount of crosslinking will be sufficient for use in at least
certain
embodiments of the present invention.
[0036]Generally speaking, the polymers used in the microparticles may
desirably be
crosslinked to a sufficient degree as to prevent, or reduce the degree of,
permanent
deformation of the microparticles when exposed to pressures, temperatures and
shear
forces expected in the course of manufacture, consumption and disposal.
Conversely,
the polymer(s) should not be crosslinked to an extent that could result in the
microparticle being brittle and/or incapable of being temporarily deformed
(even if
plasticized). Insufficient polymer crosslinking may result in excessive
difficulty in
removing cuds comprising the polymeric microparticles from environmental
surfaces. On
the other hand, excessive polymer crosslinking may result in a gum base that
has
insufficient adhesion between the microparticles and/or is excessively hard
for optimal
chewing enjoyment by the consumer.
[0037]Those of ordinary skill in the art are readily able to determine a level
of
crosslinking within these practical limits. For those requiring further
guidance, reference
can be made to ASTM method D2765, Standard Test Methods for Determination of
Gel
Content and Swell Ratio of Crosslinked Ethylene Plastics. In general, polymers
having a
gel content of at least 25%, or at least 50%, or at least 75%, as tested by
this method,
are considered to have suitable crosslinking for use in the microparticles of
the present
invention. In some embodiments, polymers having a gel content between about
80%
and 100%, as measured by ASTM D-2675, are suitable for use in the
microparticles
described herein.
[0038] Using a crosslinked polymer having an appropriate complex modulus is
expected
to at least assist in providing the present gum base with appropriate and/or
acceptable
chew properties.
[0039] More particularly, crosslinked polymers having a complex modulus G* at
25 C of
less than about 109 dyne/cm2 (108 Pa), less than about 108 dyne/cm2 (107 Pa),
less than
107 dyne/cm2 (106 Pa) or, in some embodiments, even less than about 106
dyne/cm2
(105 Pa) can assist in providing chewing gum bases and chewing gums with
desirable
chew properties. In the case of the polymer(s) having a complex modulus G* at
25 C or
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greater than about 107 or 108 dyne/cm2 (106 or 107 Pa) or even greater, it may
be
desirable to combine the polymer with a plasticizer to reduce effective
complex modulus
G* to ensure proper chewing texture. In some embodiments, the polymer may
desirably
have a complex modulus G* at 25 C of greater than about 104 dyne/cm2 (103 Pa)
or
greater than about 105 dyne/cm2 (104 Pa) or even greater than 106 dyne/cm2
(105 Pa) to
provide a firm texture during chewing.
[0040] Using a crosslinked polymer with an appropriate glass transition
temperature may
also assist in providing the gum base with appropriate and/or acceptable chew
properties. Crosslinked polymers having a glass transition temperature of less
than
about 30 C, or less than about 10 C or even less than about 0 C, are expected
to at
least assist in providing the gum base with chew properties similar to, or
better than,
conventional gum bases.
[0041] The crosslinked polymer is desirably safe for use in chewing gums, and
potentially
ingestion. In some embodiments, the polymer used will be food grade. As used
herein,
the term 'food grade' is meant to indicate that the polymer meets all legal
requirements
for use in a food product in the intended market. While requirements for being
food
grade vary from country to country, food grade polymers intended for use as
masticatory
substances (i.e. gum base) may typically have to: i) be approved by the
appropriate
local food regulatory agency for this purpose; ii) be manufactured under "Good
Manufacturing Practices" (GMPs) which may be defined by local regulatory
agencies,
such practices ensuring adequate levels of cleanliness and safety for the
manufacturing
of food materials; iii) be manufactured with food grade materials (including
reagents,
catalysts, solvents and antioxidants) or materials that at least meet
standards for quality
and purity; iv) meet minimum standards for quality and the level and nature of
any
impurities present; v) be provided with an adequately documented manufacturing
history
to ensure compliance with the appropriate standards; and/or vi) be
manufactured in a
facility that itself is subject to inspection by governmental regulatory
agencies. All of
these standards may not apply in all jurisdictions, and all that is required
in those
embodiments wherein the polymer is desirably food grade is that the polymer
meets the
standards required by the particular jurisdiction.
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[0042] For example, in the United States, ingredients are approved for use in
food
products by the Food and Drug Administration. In order to gain approval for a
new food
or color additive, a manufacturer or other sponsor must petition the FDA for
its approval.
Petition is not necessary for prior-sanctioned substances or ingredients
generally
recognized as safe (GRAS ingredients) and these are specifically included
within the
meaning of the term "food grade" as used herein. information on the regulatory
process
for food additives and colorants in the U.S. can be found at
http://www.fda.qov/Food/Food I n_gredientsPackaq inq/ucm094211. htm,
[0043] In Europe, one example of a governing agency is the European
Commission,
Enterprise and Industry. Information of the European Commission's regulation
of the
food industry in Europe can be found at
http://ec.europa.eu/entenprise/sectors/food/index en.htm,
[0044]Any polymer(s) capable of exhibiting at least a portion of the desired
properties
may be suitable for use in the microparticles, and thus gum base, described
herein.
Polymers that are capable of exhibiting the desired properties if plasticized
sufficiently
are also suitable for use. Examples of such polymers include, but are not
limited to,
grafted acrylic polymers, polyurethanes and grafted polyolefins with side
groups greater
than four carbon atoms. Graft or block copolymers of these are also suitable
[0045] Examples of polymers that are expected to exhibit the desired
properties for use
in the formation of the microparticles without the use of substantial amounts
of
plasticizer, include, but are not limited to polyacrylates, polyurethanes,
graft or block
copolymers of these. Other crosslinked polymers which might otherwise be above
the
desirable T9 and/or modulus ranges may be used if the crosslinked polymers are
suitably
plasticized to reduce the Tg and/or modulus values to within the desirable
ranges.
Combinations of any of these are also suitable. The desired polymer may
typically be
prepared from one or more monomer(s). Suitable monomers will depend upon the
polymer desirably being prepared.
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[0046] In preferred embodiments, the polymer comprises at least one
crosslinked
polyacrylate that, in further preferred embodiments may be prepared from one
or more
acrylate monomers. Suitable acrylate monomers include monofunctional
unsaturated
acrylate and/or methacrylate esters of non-tertiary alkyl alcohols, wherein
the alkyl
groups contain from about 4 to about 14 carbon atoms, and a multifunctional
crosslinking
agent.
[0047] Examples of monofunctional acrylate monomers suitable for use in
preparing the
polyacrylate thus include, but are not limited to, isooctyl acrylate, 4-methyl-
2-pentyl-
acrylate, 2-methylbutyl acrylate, isoamyl acrylate, sec-butyl acrylate, n-
butyl acrylate, 2-
ethylhexyl acrylate, isodecyl methacrylate, isononyl acrylate, isodecyl
acrylate and
mixtures thereof. Among these, isooctyl acrylate, 2-ethylhexyl acrylate, n-
butyl acrylate
or combinations of these are preferred for use in some embodiments of the gum
base.
[0048]At least one crosslinking agent may be used to produce the crosslinked
polymer.
The crosslinking agent(s) chosen, and effective amounts thereof, will depend
on the
polymer desirably crosslinked, and can be readily selected and optimized by
those of
ordinary skill in the art. In those embodiments wherein the polymer desirably
comprises
a polyacrylate, suitable crosslinking agents include multifunctional
acrylates, such as
trimethylolpropane triacrylate (TMPTA); epoxy group containing compounds;
alkylenimines; organoalkoxysilanes; or combinations of these.
[0049]The crosslinked polymer is desirably provided in the form of a
microparticle., i.e.,
a particle having a largest dimension of at least about 0.1 microns or at
least about 0.5
microns or at least about 10 microns. The microparticles may have a largest
dimension
of less than about about 1000 microns, or less than about 500 microns or less
than
about 100 microns. While not wishing to be bound by any theory, it is believed
that
providing the crosslinked polymer in such a form can assist in enhancing the
removability
of the gum bases and chewing gums, e.g., since the microparticles are of a
size that will
not allow them to flow into the topography of many environmental surfaces,
while yet
preserving the chewability of the gum bases and chewing gums.
[0050]The shape of the microparticles is not critical and they may be
irregularly shaped,
or of any shape, e.g., the particles may be in the form of rods, cylinders,
spheres, cubes,
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ovals, etc. In some embodiments, the microparticles may be generally
spherical. In
such embodiments, the generally spherical microparticles may desirably have
diameters
of from about 0.1 microns to about 1000 microns, or from about 0.5 microns to
about 500
microns, or even from about 10 microns to about 100 microns.
[0051]The desired polymer may be formed into microparticles by any of a number
of
techniques known to those of ordinary skill in the art. Or, the desired
polymer may be
purchased in a microparticle form from any of a number of commercial sources.
Polyacrylate microparticles, for example, are commercially available from
Avery
Dennison (Pasadena, California) under the tradename Ultra-Removable Adhesive.
[0052] If desirably prepared, the polymers may be provided in a microparticle
form by a
suspension polymerization process in which one or more monofunctional monomers
are
reacted along with at least one multifunctional crosslinking agent. The
reactants will be
present as suspended droplets, preferably by subjecting them to mechanical
dispersion
in an appropriate continuous phase. The particle size of the microparticles
can be
controlled by adjusting the ratio of the phases, with a greater imbalance in
the ratio
tending to produce smaller microparticles. Particle size may also be
controlled via use of
a surfactant, and the adjustment of any amounts thereof or through variations
in the
temperature of the reaction. Increasing the intensity of agitation will also
tend to produce
smaller microparticles.
[0053]Alternatively, if the microparticles are provided in the form of a water
dispersion,
they may be mechanically separated from the dispersion medium by mechanical
means
such as centrifugation, precipitation or filtration before blending with other
gum base or
chewing gum components
[0054]One exemplary method for providing the desired polymer in the form of
microparticles is described in US Patent No. 3,691,140.
[0055] Non-uniform microparticles in the form of a polymer composite can be
prepared
as follows. First, two batches of crosslinked polymeric microparticles having
different
chemical or physical properties (such as size) are prepared under an inert
(i.e. oxygen-
free) atmosphere to prevent termination of the polymerization reaction as
previously
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described. After the microparticles are substantially formed, the surfaces of
the
microparticles of both batches stay active for further growth. The two batches
are then
combined while maintaining the inert atmosphere. This allows the
microparticles to react
and covalently and/or ionically bond with each other on their surfaces to
produce the
polymer composite. Finally, oxygen is introduced into the atmosphere to
terminate the
reaction. A microparticle in the form of a polymer composite having a large
diameter
microparticle component (1) and a number of smaller diameter microparticle
components
(2) covalently bonded to its surface is illustrated in Figure 3.
[0056]Non-uniform microparticles in the form of a hollow shell can be prepared
as
follows. A template particle, such as a particle of silicon dioxide is
introduced into a
monomer emulsion or suspension. Polymerization is allowed to occur which
results in a
polymeric coating on the surface of the template particle. After
polymerization is
complete, the coated particles are collected and etched with using a reagent
capable of
dissolving the template particle but not the polymeric coating, such as a
hydrofluoric acid
solution. After the reagent has dissolved the template particles, the hollow
polymeric
microparticles are collected and washed to remove the reagent. This process is
illustrated in Figure 4. Processes for making a hollow shell microparticle of
the type
described are described in the following papers:
Template Synthesis of Hydrogel Composite Hollow Spheres Against
Polymeric Hollow Latex, by Wei Wei et al. Colloid & Polymer Science, 286, 881-
888;
Template Synthesis of Composite Hollow Spheres Using Sulfonated Polystyrene
Hollow
Spheres, By Shu-Jiang Ding et al. Polymer 47, 25, 8360-8366; and Direct
Synthesis of
Polymer Nanocapsules: Self-Assembly of Polymer Hollow Spheres Through
Irreversible
Covalent Bond Formation, by Kim D. et al. JACS 2010 132(28), 9908-19. A
photomicrograph of a hollow shell microparticle of the type described is shown
in Figure
5.
[0057] Non-uniform microparticles in the form of a core-shell can be prepared
by surface-
initiated atom transfer radical polymerization (ATRP). Such processes are
disclosed in
the following papers: PLGA-
Lecithin-PEG
Core-Shell Nanoparticles for Controlled Drug Delivery, by Robert Langer et al,
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Biomaterials 30 (2009), 1627-1634; Preparation of Core-Shell Type Polymer
Microspheres from Anionic Block Copolymers, by Koji Ishizu, Fumihiro Naruse
and Reiko
Saito Polymer, 34, 18, 1993, 3929-3933); Synthesis of Core-Shell Polymer
Microspheres
by Two-Stage Distillation-Precipitation Polymerization, by Donglai Qi, Feng
Bai, Xinlin
Yang and Wenqiang Huang, European Polymer Journal, 41, 10, 2005, 2320-2328;
and
Inorganic-Polymer Core Shell Hybrid Microspheres, by Longyu Li, Dianbin Qin,
Xinlin
Yang and Guangyu Liu, Colloid & Polymer Science, 288, 199-206. A core-shell
microparticle having a crosslinked polymer shell (3) and a solid or liquid
core (4) is
shown in Figure 6.
[0058] Microparticles in the form of nanoparticles can be prepared by altering
the
conditions used to make larger crosslinked polymeric microparticles. Such
modifications
may include using a higher emulsifier level to increase the critical micelle
concentration
(CMC), more vigorous agitation of the emulsion or a combination of these
methods.
[0059]The above described methods of forming the crosslinked polymeric
microparticles
of the present invention are exemplary only and the present invention is not
limited to the
described processes. The use of other methods, whether or not currently known,
are
specifically contemplated. Any method of producing the described crosslinked
polymeric
microbeads is acceptable. The gum bases described herein contain at least one
population of the microparticles described herein, although it is to be
understood that the
gum base may comprise any number of such populations. In such embodiments,
each
population may comprise the same polymer, but may be processed differently or
comprise different additional components, so that the properties of each
population are
different. Or, each of the populations may comprise the same polymer, but one
population of microparticles may have a different particle size distribution
or average
largest dimension than the other(s). For example, a population of
nanoparticles may be
combined with populations of microparticles having greater average largest
dimension.
Of course, each of the populations may also comprise a different polymer, or
combinations of polymers, etc. In addition, populations of microparticles in
the form of
polymer composite microparticles, hollow shell microparticles and core-shell
microparticles may be combined with each other or with populations of solid
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microparticles which comprise a single polymer or copolymer in any desired
combination. The blending of different populations of microparticles provides
greater
control and flexibility over the texture and chewing properties of the
finished product.
[0060] The microparticles may be the sole component of the gum base described
herein, or the gum base may comprise additional ingredients, if desired. For
example,
the microparticles may comprise from about 0.1 wt% to about 99 wt%, or from
about 1
wt% to about 70 wt%, or from about 5 wt% to about 40 wt%, based upon the total
weight
of the gum base.
[0061] In order to further enhance the removability of cuds formed from
chewing gums
comprising the gum bases described herein, it may be desirable to incorporate
other
known removability-enhancing features into the gum base and/or chewing gum.
[0062] For example, certain additives such as emulsifiers and amphiphilic
polymers may
be added. Another additive which may prove useful is a polymer having a
straight or
branched chain carbon-carbon polymer backbone and a multiplicity of side
chains
attached to the backbone as disclosed in WO 06-016179.
Still another additive which may enhance
removability is a polymer comprising hydrolyzable units or an ester and/or
ether of such
a polymer. One such polymer comprising hydrolyzable units is a copolymer sold
under
the Trade name Gantrez . Addition of such polymers at levels of from about 1
wt% to
about 20 wt% based upon the total weight of the chewing gum base may reduce
adhesion of discarded gum cuds.
[0063]Another approach to enhancing removability of the present invention
involves
formulating gum bases to contain less than 5% (i.e. 0 to 5%) of a calcium
carbonate
and/or talc filler and/or 5 to 40% amorphous silica filler. Formulating gum
bases to
contain 5 to 15% of high molecular weight polyisobutylene (for example,
polyisobutylene
having a weight average or number average molecular weight of at least 200,000
Daltons) is also effective in enhancing removability.
[0064] In those embodiments of the invention wherein the gum base desirably
includes
ingredients or components in addition to the microparticles, any components
typically
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found in gum bases may be included. For example, the microparticles may be
combined
with one or more elastomers, elastomer solvents, softeners, resins, fillers,
colors,
antioxidants, emulsifiers or mixtures thereof and other conventional gum base
components.
[0065] In some embodiments, the microparticles may be used as the sole
elastomer,
while in others, the microparticles may be combined with other base
elastomers, and
elastomer solvents suitable for use in gum bases.
[0066] In some embodiments, significant amounts (more than 1 wt%) of these
conventional elastomers and elastomer solvents are not incorporated into a gum
base of
the present invention, i.e., the elastomer component of gum bases disclosed
herein may
contain up to about 100 wt% of the microparticles disclosed herein.
[0067] In other embodiments, mixtures of the microparticles with any of the
elastomers
described below may be used in the present gum bases. For example, the present
gum
bases may include at least about 10 wt%, or at least about 30 wt%, or at least
about 50
wt% or even at least about 70 wt% microparticles by weight of the total
elastomer
content, in combination with any other desired elastomer(s).
[0068]A typical elastomeric component of the gum bases described herein
contains
between 10 wt% to 100 wt% microparticles and preferably 50 wt% to 100 wt%
microparticles. A gum base having an elastomer component containing from about
75
wt% to about 90 wt%, or from about 90 wt% to about 100 wt.% microparticles is
also
useful.
[0069]Suitable other elastomers, where used, include synthetic elastomers
including
polyisobutylene, isobutylene-isoprene copolymers (butyl rubber), styrene-
butadiene
copolymers, polyisoprene and combinations thereof. Natural elastomers that can
be
used include natural rubbers such as chicle, jelutong, lechi caspi, perillo,
sorva,
massaranduba balata, massaranduba chocolate, nispero, rosindinha, chicle,
gutta hang
kang, and combinations thereof. Additionally, biopolymers, such as those based
on
modified or unmodified proteins and carbohydrates, may be used as elastomers.
Such
biopolymers may have the advantage of enhancing the biodegradability of the
gum cud
after it is discarded.
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[0070]Elastomer solvents commonly used for synthetic elastomers may be
optionally
used in this invention including but are not limited to, natural rosin esters,
often called
estergums, such as glycerol esters of partially hydrogenated rosin, glycerol
esters of
polymerized rosin, glycerol esters of partially or fully dimerized rosin,
glycerol esters of
rosin, pentaerythritol esters of partially hydrogenated rosin, methyl and
partially
hydrogenated methyl esters of rosin, pentaerythritol esters of rosin, glycerol
esters of
wood rosin, glycerol esters of gum rosin; synthetics such as terpene resins
derived from
alpha-pinene, beta-pinene, and/or d-limonene; and any suitable combinations of
the
foregoing. The preferred elastomer solvents also will vary depending on the
specific
application, and on the type of elastomer which is used.
[0071]Softeners (including emulsifiers) may be added to gum bases in order to
optimize
the chewability and mouth feel of a chewing gum based upon the same.
Softeners/emulsifiers that typically are used include tallow, hydrogenated
tallow,
hydrogenated and partially hydrogenated vegetable oils, cocoa butter, mono-
and di-
glycerides such as glycerol monostearate, glycerol triacetate, lecithin,
paraffin wax,
microcrystalline wax, natural waxes and combinations thereof. Lecithin and
mono- and
di-glycerides also function as emulsifiers to improve compatibility of the
various gum
base components. Further, a typical gum base may include at least about 5 wt%,
or at
least about 10 wt% softener, or up to about 30 wt% and more typically up to
about 40
wt% softener, based upon the total weight of the gum base.
[0072]The gum bases of the present invention may optionally include plastic
resins.
These include polyvinyl acetate, vinyl acetate-vinyl laurate copolymer having
vinyl
laurate content of about 5 to about 50 percent by weight of the copolymer, and
combinations thereof. Preferred weight average molecular weights (by GPC) for
polyvinyl acetate are 2,000 to 90,000 or 10,000 to 65,000 (with higher
molecular weight
polyvinyl acetates typically used in bubble gum bases). For vinyl acetate-
vinyl laurate,
vinyl laurate content of from about 10 wt% to about 45 wt% of the copolymer is
preferred. Where used, plastic resins may constitute 5 to 35 wt.% of the gum
base
composition.
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[0073] Fillers/texturizers typically are inorganic, water-insoluble powders
such as
magnesium and calcium carbonate, ground limestone, silicate types such as
magnesium
and aluminum silicate, clay, alumina, talc, titanium oxide, mono-, di- and tri-
calcium
phosphate and calcium sulfate. Insoluble organic fillers including cellulose
polymers
such as wood as well as combinations of any of these also may be used. If
used, fillers
may typically be included in amounts from about 4 wt% to about 50 wt% filler,
based
upon the total weight of the gum base. However, in some embodiments, it is
preferred
that the use of common inorganic fillers be minimized such as by limiting
their use to less
than 5 wt.% and preferably less than 3 wt.% or even 0 percent as a means of
further
reducing the adhesive properties of the chewed cud.
[0074]Colorants and whiteners may include FD&C-type dyes and lakes, fruit and
vegetable extracts, titanium dioxide, and combinations thereof. Antioxidants
such as
BHA, BHT, tocopherols, propyl gallate and other food acceptable antioxidants
may be
employed to prevent oxidation of fats, oils and elastomers in the gum base.
[0075]The gum base described herein may include wax or be wax-free. An example
of
a wax-free gum base is disclosed in U.S. Patent No. 5,286,500.
It is preferred that the gum bases of the present invention be free of
paraffin wax.
[0076]A typical gum base useful in this invention may include from about 0.1
wt% to
about 98 wt% microparticles, from about 0 wt% to about 20 wt% synthetic
elastomer,
from about 0 wt% to about 20 wt% natural elastomer, from about 0 wt% to about
40 wt%
elastomer solvent, from about 0 wt% to about 50 wt% filler/texturizer, from
about 0 wt%
to about 40 wt.% softener/emulsifier, from about 5 wt% to about 35 wt% plastic
resin,
and about 2 wt% or less, or less than about 1 wt% of miscellaneous ingredients
such as
colorants, antioxidants, and the like.
[0077]The microparticles may be processed into the gum base according to any
known
method of doing so. The microparticles may be used as prepared or purchased,
typically
in an aqueous suspension. In those embodiments wherein the microparticles are
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provided or purchased as a suspension, the microparticle suspension may be
dehydrated prior to inclusion in, or use as, the gum base.
[0078] If used as an aqueous suspension, one exemplary method of manufacturing
a
gum base comprising the polymeric microparticles includes adding the
microparticle
suspension to a mixer followed by at least one of an elastomer, an elastomer
solvent, a
filler/texturizer, emulsifier/softener, plastic resin, color and/or
antioxidant to the mixer.
the desired components are mixed at elevated temperature, e.g., from about 100
C to
about 120 C, for a time sufficient to evaporate at least a majority of the
liquid, and
discharging the gum base from the mixer. Any desired additional ingredients
may be
added by conventional batch mixing processes or continuous mixing processes.
Process temperatures are generally from about 120 C to about 180 C in the case
of a
batch process.
[0079] If it is desired to combine the polymeric microparticles with
conventional
elastomers, it is preferred that the conventional elastomers be formulated
into a
conventional gum base before combining with the microparticle gum base.
[0080] To produce a conventional gum base, the elastomers are typically first
ground or
shredded along with at least a portion of any desired filler. Then the ground
elastomer is
transferred to a batch mixer for compounding. Any standard, commercially
available
mixer (e.g., a Sigma blade mixer) may be used for this purpose. Compounding
typically
involves combining the ground elastomer with filler and elastomer solvent and
mixing
until a homogeneous mixture is produced, typically for about 30 to about 70
minutes.
[0081] Thereafter, any desired additional filler and elastomer plasticizer(s)
are added
followed by softeners, while mixing to homogeneity after each addition.
Minor
ingredients such as antioxidants and color may be added at any time in the
process.
The conventional base is then blended with the microparticle-containing gum
base in the
desired ratio.
[0082] Where microparticles are combined with conventional elastomers and/or
other
base components, the completed base may be extruded or cast into any desirable
shape
(e.g., balls, pellets, sheets or slabs) and allowed to cool and solidify. In
some cases, it
may be preferable to use an underwater pelletization process for this purpose.
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[0083]Alternatively, the gum base may be compounded with both conventional
elastomers and microparticles, or, any desired conventional elastomers and the
polymeric microparticles may be added separately to a gum base mixing
operation along
with other chewing gum components.
[0084]Continuous processes using mixing extruders, which are generally known
in the
art, may also be used to prepare the gum base. In a typical continuous mixing
process,
initial ingredients (including ground elastomer, if used) are metered
continuously into
extruder ports various points along the length of the extruder corresponding
to the batch
processing sequence. If the microparticles are to be compounded into the base,
a
metering extruder or other specialized means to meter the microparticles into
the
compounding extruder may be used.
[0085]After the initial ingredients have mixed homogeneously and have been
sufficiently
compounded, the balance of the base ingredients are metered into ports or
injected at
various points along the length of the extruder. Typically, any remainder of
elastomer
component or other components are added after the initial compounding stage.
The
composition is then further processed to produce a homogeneous mass before
discharging from the extruder outlet. Typically, the transit time through the
extruder will
be less than an hour.
[0086] Exemplary methods of extrusion, which may optionally be used in
accordance
with the present invention, include the following:
(i) U.S. Pat. No. 6,238,710, which describes a method for continuous chewing
gum base manufacturing, which entails compounding all ingredients in a single
extruder;
(ii) U.S. Pat. No. 6,086,925 which discloses the manufacture of chewing gum
base by
adding a hard elastomer, a filler and a lubricating agent to a continuous
mixer; (iii) U.S.
Pat. No. 5,419,919 which discloses continuous gum base manufacture using a
paddle
mixer by selectively feeding different ingredients at different locations on
the mixer; and,
(iv) U.S. Pat. No. 5,397,580 which discloses continuous gum base manufacture
wherein
two continuous mixers are arranged in series and the blend from the first
continuous
mixer is continuously added to the second extruder.
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[0087]A typical gum base comprising the microparticles as described herein may
desirably have a shear modulus (the measure of the resistance to the
deformation) of
from about 1 kPa (10000 dyne/cm2) to about 600 kPa (6 x 106 dyne/cm2) at 40 C
(measured on a Rheometric Dynamic Analyzer with dynamic temperature steps, 0-
100 C
at 3 C/min; parallel plate; 0.5% strain; 10 rad/s). A preferred gum base
according to
some embodiments of the present invention may have a shear modulus of from
about 5
kPa (50000 dyne/cm2) to about 300 kPa (3 x 106 dyne/cm2), or even from about
10 kPa
(1 x 105 dyne/cm2) to about 70 kPa (7 x 105 dyne/cm2).
[0088]A variety chewing gum formulations including the gum bases described
herein
can be created and/or manufactured in accordance with the present invention.
Because
of the inclusion of the polymeric microparticles described herein into the
inventive gum
base and chewing gum, a gum cud formed from the chewing gum is more easily
removed from surfaces onto which it may become adhered than gum cuds formed
from
chewing gums comprising conventional gum bases.
[0089] The gum base described herein may constitute from about 0.1 wt% to
about 98
wt% by weight of the chewing gum. More typically, the inventive gum base may
constitute from about 10 wt% to about 50 wt% of the chewing gum and, in
various
preferred embodiments, may constitute from about 20 wt% to about 35% by weight
of
the chewing gum.
[0090] In some embodiments, the gum bases described herein may be used to
replace
conventional gum bases in chewing gum formulas. In such embodiments, the gum
base
may comprise from about 15 wt% to about 50 wt% of the chewing gum.
[0091] Or, the gum bases described herein may be used in combination with
conventional gum bases, in any amount or ratio. In such embodiments, the gum
base
described herein may comprise from about 0.1 wt% to about 30 wt% of the
chewing
gum.
[0092]Any of the removability enhancing components discussed herein may also
be
added to the chewing gum, either instead of, or in addition to, any amount
thereof added
to the gum base. For example, a polymer comprising hydrolysable units or an
ester or
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ether of such a polymer may be added to the chewing gum at levels of from
about 1 wt%
to about 7 wt% based upon the total weight of the chewing gum.
[0093]Further, in some embodiments, high levels of emulsifiers such as
powdered
lecithin may be incorporated into the chewing gum at levels of 3 to 7% by
weight of the
chewing gum in order to enhance the removability of gum cuds produced
therefrom. In
such embodiments, it may be advantageous to spray dry or otherwise encapsulate
the
emulsifier to delay its release.
[0094]Any combination of any number of the described approaches may be
employed
simultaneously to achieve improved removability. Further, and as described
above, the
described removability enhancing components, or any other components known to
those
of ordinary skill in the art to be useful for this purpose, may be
incorporated into the gum
base and/or chewing gum.
[0095] In one exemplary embodiment, removability of gum cuds formed from the
chewing
gums comprising the gum bases disclosed herein can be further enhanced by
incorporating at least one of from about 0 wt% to about 5 wt% of a calcium
carbonate or
talc filler, from about 5 wt% to about 40 wt% amorphous silica filler, from
about 5 wt% to
about 15 wt% high molecular weight polyisobutylene, from about 1 wt% to about
20 wt%
of a polymer having a straight or branched chain carbon-carbon polymer
backbone and a
multiplicity of side chains attached to the backbone, based upon the total
weight of the
gum base, into the gum base. The gum base according to this embodiment may
then be
formed into a chewing gum further comprising 3 to 7% of an emulsifier, such as
lecithin,
which is preferably encapsulated such as by spray drying.
[0096] In addition to the gum base, chewing gum typically includes a bulk
portion which
may include bulking agents, high intensity sweeteners, one or more flavoring
agents,
water-soluble softeners, binders, emulsifiers, colorants, acidulants,
antioxidants, and
other components that provide attributes desired by consumers of chewing gum.
Any or
all of these may be included in the present chewing gums.
[0097] In some embodiments, one or more bulking agent(s) or bulk sweetener(s)
may be
provided in chewing gums described herein to provide sweetness, bulk and
texture to the
chewing gum. Bulking agents may also be selected to allow marketing claims to
be used
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in association with the chewing gums. That is, if it is desirable to promote a
chewing
gum as low calorie, low calorie bulking agents such as polydextrose may be
used, or, if
the chewing gum is desirably promoted as comprising natural ingredients,
natural bulking
agents such as isomaltulose, inulin, agave syrup or powder, erythritol,
starches and
some dextrins may be used. Combinations of any of the above bulking agents may
also
be used in the present invention.
[0098]Typical bulking agents include sugars, sugar alcohols, and combinations
thereof.
Sugar bulking agents generally include saccharide-containing components
commonly
known in the chewing gum art, including, but not limited to, sucrose,
dextrose, maltose,
dextrin, dried invert sugar, fructose, levulose, galactose, corn syrup solids,
and the like,
alone or in combination. In sugarless gums, sugar alcohols such as sorbitol,
maltitol,
erythritol, isomalt, mannitol, xylitol and combinations thereof are
substituted for sugar
bulking agents.
[0099] Bulking agents typically constitute from about 5 wt% to about 95 wt% of
the total
weight of the chewing gum, more typically from about 20 wt% to about 80 wt%
and, still
more typically, from about 30 wt% to about 70 wt% of the total weight of the
chewing
gum.
[00100]
If desired, it is possible to reduce or eliminate the bulking agent to provide
a reduced calorie or calorie-free chewing gum.
In such embodiments, the
microparticles/gum base may comprise up to about 98 wt% of the chewing gum.
Or, a
low caloric bulking agent can be used. Examples of low caloric bulking agents
include,
but are not limited to, polydextrose; Raftilose; Raftilin;
fructooligosaccharides
(NutraFlora0); Palatinose oligosaccharide; Guar Gum Hydrolysate (Sun Fiber );
or
indigestible dextrin (Fibersol0). The caloric content of a chewing gum can
also be
reduced by increasing the relative level of gum base while reducing the level
of caloric
sweeteners in the product. This can be done with or without an accompanying
decrease
in piece weight.
[00101]
For example, in these and other embodiments, high intensity artificial
sweeteners can be used alone or in combination with the bulk sweeteners.
Preferred
sweeteners include, but are not limited to sucralose, aspartame, salts of
acesulfame,
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alitame, neotame, saccharin and its salts, cyclamic acid and its salts,
glycyrrhizin, stevia
and stevia derivatives such as Rebaudoside A, dihydrochalcones, lo han guo,
thaumatin,
monellin, etc., or combinations of these. In order to provide longer lasting
sweetness
and flavor perception, it may be desirable to encapsulate or otherwise control
the release
of at least a portion of the artificial sweetener. Techniques such as wet
granulation, wax
granulation, spray drying, spray chilling, fluid bed coating, coacervation,
and fiber
extrusion may be used to achieve the desired release characteristics.
[00102] Usage level of the artificial sweetener will vary greatly and will
depend on
such factors as potency of the sweetener, rate of release, desired sweetness
of the
product, level and type of flavor used and cost considerations. Generally
speaking,
appropriate levels of artificial sweeteners thus may vary from about 0.02 wt%
to about 8
wt%. When carriers used for encapsulation are included, the usage level of the
encapsulated sweetener will be proportionately higher.
[00103] A variety of natural or artificial flavoring agents, and may be
used in any
number or combination, if desired. Flavoring agents may include essential
oils, natural
extracts, synthetic flavors or mixtures thereof including, but not limited to,
oils derived
from plants and fruits such as citrus oils, fruit essences, peppermint oil,
spearmint oil,
other mint oils, clove oil, oil of wintergreen, anise and the like.
[00104] Artificial flavoring agents and components may also be used.
Sensate
components which impart a perceived tingling or thermal response while
chewing, such
as a cooling or heating effect, also may be included. Such components include
cyclic
and acyclic carboxamides, menthol and menthol derivatives such as menthyl
esters of
food acceptable acids, and capsaicin among others. Acidulants may be included
to
impart tartness.
[00105] The desired flavoring agent(s) can be used in amounts of from
approximately 0.1 wt% to about 15 wt% of the gum, and preferably, from about
0.2 wt%
to about 5 wt%.
[00106] Water-soluble softeners, which may also be known as water-soluble
plasticizers, plasticizing agents, binders or binding agents, generally
constitute between
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approximately 0.5 wt% to about 15 wt% of the chewing gum. Water-soluble
softeners
may include glycerin, propylene glycol, and combinations thereof.
[00107] Syrups
or high-solids solutions of .sugars and/or sugar alcohols such as
sorbitol solutions, hydrogenated starch hydrolysates (HSH), corn syrup and
combinations thereof, may also be used. In the case of sugar gums, corn syrups
and
other dextrose syrups (which contain dextrose and significant amounts higher
saccharides) are most commonly employed. These include syrups of various DE
levels
including high-maltose syrups and high fructose syrups. In some cases, low-
moisture
syrups can replace some or all of the bulking agents typically use, in which
case usage
levels of the syrup may extend up to 50 wt.% or more of the total gum
composition. In
the case of sugarless products, solutions of sugar alcohols including sorbitol
solutions
and hydrogenated starch hydrolysate syrups are commonly used.
[00108] Also
useful are syrups such as those disclosed in US 5,651,936 and US
2004-234648. Such
syrups serve to soften
the initial chew of the product, reduce crumbliness and brittleness and
increase flexibility
in stick and tab products. They may also control moisture gain or loss and
provide a
degree of sweetness depending on the particular syrup employed.
[00109] In
some embodiments, an active agent such as a drug, a dental health
ingredients or dietary supplement can be used in combination with the gums and
gum
bases of the present invention. In such cases, the active agent may be
incorporated into
the gum base, the chewing gum or into associated non-gum portions of a
finished
product such as into a coating or a candy layer. In some cases, the active may
be
encapsulated to control its release or to protect it from other product
ingredients or
environmental factors.
[00110] The
chewing gum formulations provided herein may also comprise one or
more other ingredients conventional in the art, such as gum emulsifiers,
colorants,
acidulants, fillers, antioxidants and the like. Such ingredients may be used
in the present
chewing gum formulations in amounts and in accordance with procedures well
known in
the art of chewing gum manufacture.
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[00111] Chewing gum is generally manufactured by sequentially adding the
various
chewing gum ingredients, including the gum base, to commercially available
mixers
known in the art. After the ingredients have been thoroughly mixed, the
chewing gum
mass is discharged from the mixer and shaped into the desired form, such as by
rolling
into sheets and cutting into sticks, tabs or pellets or by extruding and
cutting into chunks.
[00112] In some embodiments, the chewing gum may be prepared according to
a
batch process. In such a process, the ingredients are mixed by first melting
the gum
base and adding it to the running mixer. The gum base may alternatively be
melted in
the mixer. Color and emulsifiers may be added at this time.
[00113] A chewing gum softener such as glycerin can be added next along
with a
portion of the bulking agent. Further portions of the bulking agent may then
be added to
the mixer. Flavoring agents are typically added with the final portion of the
bulking
agent. The entire mixing process typically takes from about five to about
fifteen minutes,
although longer mixing times are sometimes required.
[00114] In other embodiments, it may be possible to prepare the gum base
and
chewing gum in a single high-efficiency extruder as disclosed in U.S. Patent
No.
5,543,160. Chewing gums of the present invention may be prepared by a
continuous
process comprising the steps of: a) adding gum base ingredients into a high
efficiency
continuous mixer; b) mixing the ingredients to produce a homogeneous gum base,
c)
adding at least one sweetener and at least one flavor into the continuous
mixer, and
mixing the sweetener and flavor with the remaining ingredients to form a
chewing gum
product; and d) discharging the mixed chewing gum mass from the single high
efficiency
continuous mixer. In yet another alternative, a finished gum base may be
metered into a
continuous extruder along with other gum ingredients to continuously produce a
chewing
gum composition.
[00115] The resultant chewing gums may be formed into sticks, tabs,
chunks,
tapes, coated or uncoated pellets or balls or any other desired form. In some
embodiments, the chewing gum formulation may be used as a component of a
greater
confectionery product, for example as a center in a hard candy such as a
lollipop or as
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one or more layers of a layered confection which also comprises non-gum
confectionery
layers.
[00116] Of course, many variations on the basic gum base and chewing gum
mixing processes are possible.
EXAMPLES
[00117] The following examples of the invention and comparative run
illustrate
certain aspects and embodiments of the present invention, but do not limit the
invention
described and claimed. Amounts listed are in weight percent, based upon the
total
weight of the gum base, or chewing gum, as the case may be.
[00118] EXAMPLES 1-6
[00119] Polyacrylate Microparticles Polyacrylate microparticles (Ultra-
Removable
Adhesive) were acquired from Avery Dennison.
[00120] Gum Bases Three gum bases_were prepared, the formulas of which are
provided below in Table 1. Briefly, Gum Base A was used as a control, and was
based
upon a commercial formula known to be strongly adhesive to concrete. Gum Base
B
was formulated to have reduced adhesion to environmental surfaces. Gum Base C
comprised polyacrylate microparticles as described herein.
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TABLE 1
Ingredient Gum Base A Gum Base B Gum Base C
(strongly adhesive (sample according (microparticles)
sample) to W0-01024640)
Butyl Rubber 8.67 10.78 ---
Polyisobutylene 1.60 ---
Polyvinyl acetate 23.91 23.72 ---
Terpene resin 22.24 31.81 ---
Hydrogenated 17.69 29.87 ---
vegetable oil
Lecithin 3.23 ----
Calcium carbonate 22.60 3.77 ---
BHA 0.06 0.05 ---
Polyacrylate --- --- 100.00
microparticles
Total 100.00 100.00 100.00
[00121] Gum Base A was made in a sigma blade mixer at 120 C. For a batch
of
3000 gram, gum base A was made in according to the sequence shown in Table 2,
below.
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TABLE 2
addition time
Gum base A cyo (hr:min)
Butyl rubber 8.67 start
Polyisobutylene 1.6 start
calcium carbonate 15 Start
terpene resin 10 Start
terpene resin 12.24 0:30
calcium carbonate 7.6 0:30
polyvinyl acetate 13.91 0:40
polyvinyl acetate 10 0:50
hydrogeneated vetetable
oil 10 1:00
hydrogeneated vetetable
oil 7.69 1:10
Lecithin 3.23 1:10
BHA 0.06 1:10
Done 1:30
[00122] Gum Base B was made in a sigma blade mixer at 120 C. For a batch
of
3000 gram, Gum Base B was made in according to the sequence shown in Table 3,
below.
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TABLE 3
addition time
Gum base B cyo (hr:min)
Butyl rubber 10.78 start
calcium carbonate 3.77 start
terpene resin 20 start
terpene resin 11.81 0:30
polyvinyl acetate 13.72 0:40
polyvinyl acetate 10 0:50
hydrogeneated
vetetable oil 10 1:00
hydrogeneated
vetetable oil 10 1:10
hydrogeneated
vetetable oil 9.87 1:20
BHA 0.05 1:20
Done 1:40
[00123] Chewing Gums Six chewing gum formulations were prepared, two
comparative and four inventive. Example 1, a comparative formulation, was
prepared
using Gum Base A, known to be strongly adhesive to concrete. Example 2 was
prepared using Gum Base B and so appropriate for use as a reduced adhesion
control/comparative example. Examples 3-6 were prepared using a combination of
Gum
Base B (reduced adhesion control) and inventive Gum Base C.
[00124] Chewing Gums 1-6 were made in a 1000 gram batch sigma blade mixer.
The gum base and bulk sweeteners (sorbitol) were pre-heated in 70 C oven for
30
minutes. The blend of gum base and sorbitol was then added in the running
mixer (front
blade speed 32 rpm), the other ingredients (except flavor) were added
immediately and
mixed for four to five minutes. The flavor was then added and mixed for an
additional 4
to 5 minutes until a homogeneous appearance was achieved.
[00125] The formulations for Examples 1-6 are shown in Table 4, below.
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TABLE 4
Ingredient Example Example Example Example Example Example
1 2 3 4 5 6
(Adhesive (Reduced (Inventive) (Inventive) (Inventive) (Inventive)
control) adhesion
control)
Gum Base A 32.33 -- --
Gum Base B -- 33.67 10.00 16.50 23.00
23.47
Gum Base C -- -- 23.00 16.50 10.00
10.20
(Micro-
particles)
Sorbitol 45.50 58.60 59.89 59.89 59.89
58.60
Calcium 12.74 -- -- -- -- --
Carbonate
Glycerin 3.92 4.08 4.00 4.00 4.00
4.08
Maltitol 2.02 -- -- -- -- --
Peppermint 1.91 1.99 1.49 1.49 1.49
1.99
Flavor
Lecithin 0.44 0.46 0.45 0.45 0.45
0.46
Menthol 0.34 0.36 0.35 0.35 0.35
0.36
Encapsulated 0.33 0.35 0.34 0.34 0.34
0.35
Acesulfame K
Encapsulated 0.33 0.35 0.34 0.34 0.34
0.35
Aspartame
Aspartame 0.14 0.14 0.14 0.14 0.14
0.14
Total 100.00 100.00 100.00 100.00 100.00
100.00
[00126] Both Examples 3 and 4 were very elastic, exhibiting good shape
memory.
Examples 5 and 6 were closer to conventional gum, and could be sheeted and cut
through.
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[00127] Removability The removability of the chewing gums prepared at
Examples
1-6 was tested as follows.
[00128] Cud preparation: The gum samples were immobilized in a metal sieve
and
immersed in 30 C circulating water for 16 hours, then finger kneaded in 30 C
water for 2
minutes.
[00129] Gum cud placement on paver: A concrete paver was rinsed with tap
water
and air dried overnight. The paver was set on flat ground with the flat
surface face up. A
fresh gum cud was placed in the center of the paver. The cud was immediately
covered
by a silicone pad with another paver on the top. A person weighing
approximately 200
lbs wearing the flat-heel shoes stepped on the paver for 2 seconds.
[00130] Gum cud ageing: 45 C/60RH for 24 hours, and then ambient ageing
over
night.
[00131] Removability Test: Power Wash (1550 PSI). The nozzle angle was set
at
60 degrees from the ground, and the spray pattern was set to a fan shape
covering 3 cm
width on ground when the nozzle was held 40 cm from the cud. The cud was
washed for
up to 1 minute. A photo was taken before and after the removal test, using a
one cent
coin as a reference mark for photographic analysis. The percentage of residue
remaining after pressure washing was estimated from the after photo. If the
cud was
completely removed during power wash, the removal time was recorded.
[00132] The results of the removability test are summarized below in Table
5.
TABLE 5
Example Example Wash time % Residue Remaining
Description (sec)
1 Adhesive Control 60 95
2 Reduced Adhesion 15 0
Control
3 Inventive ¨ 23% 2 0
Microparticles
4 Inventive ¨ 16.5% 3 0
Microparticles
Inventive ¨ 10% 6 0
Microparticles
6 Inventive ¨ 10% 6 0
Microparticles
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[00133] As shown, each of the inventive chewing gums (according to
Examples 3-
6) not only showed superior removability as compared to the adhesive control
chewing
gum formulation, but also showed superior removability as compared to the
reduced
adhesion control.
[00134] Rheology testing Gum cuds were prepared of the chewing gum
formulations of Example 2 (reduced adhesion control) and Example 6 (inventive)
following the cud preparation procedure described above. The shear rheology of
the two
cuds was measured by a TA RDAIII rheometer at 37 C to determine the effect of
the
polyacrylate microparticles on chewing gum texture. The results, shown in
Figures 1 and
2, indicate that the microparticles rendered the gum cud of the inventive
chewing gum
formulation softer and more elastic than the gum cud of the reduced adhesion
control
chewing gum formulation.
[00135] Example 7
[00136] Chewing Gum A chewing gum according to the present invention,
comprising polyacrylate microparticles as a total replacement for gum base,
was made
according to the formula in Table 6.
TABLE 6
Example 7
(Inventive)
Sorbitol 45.46
Polyacrylate 33.33
Microparticles
(Dry Basis)
Calcium 15.15
Carbonate
Glycerin 4.04
Flavor 2.02
100.00
[00137] The polyacrylate microparticles were provided as a 45% aqueous
suspension to which was added the sorbitol, calcium carbonate and glycerin.
The
composition was mixed for 10 minutes to obtain a homogeneous white suspension.
The
mixture was then heated with continued mixing to obtain a thick but pourable
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suspension. Flavor was added and the mixture was allowed to dry in an oven at
50 C
overnight.
[00138] Removability Samples of commercial gums (Doublemint0 and
Orbit ) and
were obtained for use as controls for adhesion testing. All gum products were
pretreated
as follows: A small ball of the each gum product was placed in a wire net
sample holder
and placed in an ultrasonic cleaning device, filled with water. The sample was
kneaded
for 3 minutes and left in the sonic cleaner to extract water soluble
components for a total
of 9 minutes, to obtain a simulated gum cud. The surface water of the gum cud
was
dried before performing the following removability tests.
[00139] Concrete Removability Testing:
[00140] Each gum cud was applied to a piece of concrete and covered
by silicone
coated paper before stepping on it for 2 seconds. The adhered samples were
placed in
an oven at 50 C for 24 hours. The concrete was then taken out of the oven and
allowed
to cool to room temperature before attempting to remove the adhered cuds using
fingers.
The Doublemint gum cud left a large amount of residue that was very hard to
remove.
When pulled, the Orbit gum cud gave a long string and also left a large
amount of
residue. The gum cud of Example 7 was removed cleanly by hand leaving no
residue.
[00141] Fabric Removability Testing:
[00142] The gum cud of Example 7 was placed on a piece of 100% cotton
fabric
from a sport shirt and heavy thumb pressure was applied. It was cleanly
removable from
the cotton fabric using only fingers.
[00143]
While
only certain features of the invention have been illustrated and described
herein, many
modifications and changes will occur to those skilled in the art. The scope of
the claims
should not be limited by the preferred embodiments set forth in the examples,
but should
be given the broadest interpretation consistent with the description as a
whole.
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