U.S. patent application number 14/778727 was filed with the patent office on 2016-02-11 for agent for the formation of channels in an entrained polymer, entrained polymer containing such an agent, process for producing such an entrained polymer and product containing the same.
The applicant listed for this patent is CSP TECHNOLOGIES, INC.. Invention is credited to Ralf Kibele, Julien Klein, William Frederick Spano.
Application Number | 20160039955 14/778727 |
Document ID | / |
Family ID | 50483584 |
Filed Date | 2016-02-11 |
United States Patent
Application |
20160039955 |
Kind Code |
A1 |
Klein; Julien ; et
al. |
February 11, 2016 |
AGENT FOR THE FORMATION OF CHANNELS IN AN ENTRAINED POLYMER,
ENTRAINED POLYMER CONTAINING SUCH AN AGENT, PROCESS FOR PRODUCING
SUCH AN ENTRAINED POLYMER AND PRODUCT CONTAINING THE SAME
Abstract
An entrained polymer includes a base polymer, an active agent
that is immiscible with the base polymer and reacts with a selected
material, and a channeling agent that is a water insoluble polymer,
is immiscible with the base polymer, and has an affinity to
transmit the selected material through the entrained polymer at a
faster rate than in solely the base polymer.
Inventors: |
Klein; Julien; (BRUMATH,
FR) ; Spano; William Frederick; (Auburn, AL) ;
Kibele; Ralf; (BRUCKMUEHL, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CSP TECHNOLOGIES, INC. |
Auburn |
AL |
US |
|
|
Family ID: |
50483584 |
Appl. No.: |
14/778727 |
Filed: |
March 14, 2014 |
PCT Filed: |
March 14, 2014 |
PCT NO: |
PCT/US14/27452 |
371 Date: |
September 21, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61783029 |
Mar 14, 2013 |
|
|
|
Current U.S.
Class: |
525/184 ;
525/384; 525/386 |
Current CPC
Class: |
B32B 27/32 20130101;
Y10T 428/1352 20150115; Y10T 428/31938 20150401; C08L 71/02
20130101; C08L 23/12 20130101; C08F 110/06 20130101; B01J 20/28026
20130101 |
International
Class: |
C08F 110/06 20060101
C08F110/06 |
Claims
1.-49. (canceled)
50. A method of producing an entrained polymer, the entrained
polymer comprising a base polymer, an active agent that is
immiscible with the base polymer and acts on, interacts or reacts
with a selected material, and a channeling agent that is immiscible
with the base polymer and has an affinity to transmit a selected
material through the entrained polymer at a faster rate than in
solely the base polymer, wherein the channeling agent is a water
insoluble polymer, the method comprising: heating the base polymer
above its melting point, to produce a molten state; blending the
active agent and the channeling agent into the base polymer to
uniformity, to produce an entrained polymer mixture; and cooling
the entrained polymer mixture to solidify.
51. The method of claim 50, wherein the entrained polymer results
in at least two times lower extractables than a reference entrained
polymer having a reference channeling agent in a weight percentage
substantially equivalent to that of the channeling agent, wherein
the reference channeling agent is selected from the group
consisting of a polyethylene glycol, a polyethylene oxide and a
combination of a polyethylene glycol and a polyethylene oxide.
52. The method of claim 50, wherein the channeling agent has a
migration in compliance with at least one member selected from the
group consisting of: United States Pharmacopeia Standard 661
regarding physiochemical tests to plastics and heavy metals and
nonvolatile residue in polyethylene containers, European Union
Regulation No. 10/2011 of Jan. 14, 2011, and Notification No. 20 of
the Japanese Ministry of Welfare regarding food packaging and
containers.
53. The method of claim 50, wherein the channeling agent is a
propylene oxide polymerisate-monobutyl ether or a propylene oxide
polymerisate.
54. The method of claim 50, wherein the channeling agent is a
member selected from the group consisting of: an ethylene vinyl
acetate, a nylon 6 and a nylon 66.
55. The method of claim 50, wherein the active agent is a desiccant
or an oxygen absorber.
56. The method of claim 50, wherein the base polymer is
polypropylene.
57. The method of claim 50, wherein the base polymer is
polypropylene present in an amount of 24% to 60%, the active agent
is molecular sieve present in an amount of 40% to 70%, and the
channeling agent is a propylene oxide polymerisate-monobutyl ether
present in an amount of 2% to 10%.
58. A method of producing an entrained polymer, the entrained
polymer comprising a base polymer, an active agent that is
immiscible with the base polymer and acts on, interacts or reacts
with a selected material, and a channeling agent that is immiscible
with the base polymer and has an affinity to transmit a selected
material through the entrained polymer at a faster rate than in
solely the base polymer, wherein the channeling agent is a water
insoluble polymer, the method comprising: blending to uniformity
the active agent, base polymer, and channeling agent below the
melting points thereof; heating the active agent, base polymer, and
channeling agent above the melting point of one or more of the base
polymer and channeling agent, to produce an entrained polymer
mixture in a molten state; and cooling the entrained polymer
mixture to solidify.
59. The method of claim 58, wherein the entrained polymer results
in at least two times lower extractables than a reference entrained
polymer having a reference channeling agent in a weight percentage
substantially equivalent to that of the channeling agent, wherein
the reference channeling agent is selected from the group
consisting of a polyethylene glycol, a polyethylene oxide and a
combination of a polyethylene glycol and a polyethylene oxide.
60. The method of claim 58, wherein the channeling agent has a
migration in compliance with at least one member selected from the
group consisting of: United States Pharmacopeia Standard 661
regarding physiochemical tests to plastics and heavy metals and
nonvolatile residue in polyethylene containers, European Union
Regulation No. 10/2011 of Jan. 14, 2011, and Notification No. 20 of
the Japanese Ministry of Welfare regarding food packaging and
containers.
61. The method of claim 58, wherein the channeling agent is a
propylene oxide polymerisate-monobutyl ether or a propylene oxide
polymerisate.
62. The method of claim 58, wherein the channeling agent is a
member selected from the group consisting of: an ethylene vinyl
acetate, a nylon 6 and a nylon 66.
63. The method of claim 58, wherein the active agent is a desiccant
or an oxygen absorber.
64. The method of claim 58, wherein the base polymer is
polypropylene.
65. The method of claim 58, wherein the base polymer is
polypropylene present in an amount of 24% to 60%, the active agent
is molecular sieve present in an amount of 40% to 70%, and the
channeling agent is a propylene oxide polymerisate-monobutyl ether
present in an amount of 2% to 10%.
66. A method of producing an entrained polymer, the entrained
polymer comprising a base polymer, an active agent that is
immiscible with the base polymer and acts on, interacts or reacts
with a selected material, and a channeling agent that is immiscible
with the base polymer and has an affinity to transmit a selected
material through the entrained polymer at a faster rate than in
solely the base polymer, wherein the channeling agent is a water
insoluble polymer, the method comprising: heating the base polymer
above its melting point, to produce a molten state; blending the
channeling agent into the base polymer; blending the active agent
into the base polymer and the channeling agent to form an entrained
polymer mixture; and cooling the entrained polymer mixture to
solidify.
67. The method of claim 66, wherein the entrained polymer results
in at least two times lower extractables than a reference entrained
polymer having a reference channeling agent in a weight percentage
substantially equivalent to that of the channeling agent, wherein
the reference channeling agent is selected from the group
consisting of a polyethylene glycol, a polyethylene oxide and a
combination of a polyethylene glycol and a polyethylene oxide.
68. The method of claim 66, wherein the channeling agent has a
migration in compliance with at least one member selected from the
group consisting of: United States Pharmacopeia Standard 661
regarding physiochemical tests to plastics and heavy metals and
nonvolatile residue in polyethylene containers, European Union
Regulation No. 10/2011 of Jan. 14, 2011, and Notification No. 20 of
the Japanese Ministry of Welfare regarding food packaging and
containers.
69. The method of claim 66, wherein the channeling agent is a
propylene oxide polymerisate-monobutyl ether or a propylene oxide
polymerisate.
70. The method of claim 66, wherein the channeling agent is a
member selected from the group consisting of: an ethylene vinyl
acetate, a nylon 6 and a nylon 66.
71. The method of claim 66, wherein the active agent is a desiccant
or an oxygen absorber.
72. The method of claim 66, wherein the base polymer is
polypropylene.
73. The method of claim 66, wherein the base polymer is
polypropylene present in an amount of 24% to 60%, the active agent
is molecular sieve present in an amount of 40% to 70%, and the
channeling agent is a propylene oxide polymerisate-monobutyl ether
present in an amount of 2% to 10%.
74. A method of producing an entrained polymer, the entrained
polymer comprising a base polymer, an active agent that is
immiscible with the base polymer and acts on, interacts or reacts
with a selected material, and a channeling agent that is immiscible
with the base polymer and has an affinity to transmit a selected
material through the entrained polymer at a faster rate than in
solely the base polymer, wherein the channeling agent is a water
insoluble polymer, the method comprising: blending the channeling
agent and base polymer below the melting points thereof; blending
the active agent into the base polymer and channeling agent, to
uniformity; heating the channeling agent, base polymer and active
agent above the melting point of at least one of the channeling
agent or base polymer, to produce an entrained polymer mixture in a
molten state; and cooling the entrained polymer mixture to
solidify.
75. The method of claim 74, wherein the entrained polymer results
in at least two times lower extractables than a reference entrained
polymer having a reference channeling agent in a weight percentage
substantially equivalent to that of the channeling agent, wherein
the reference channeling agent is selected from the group
consisting of a polyethylene glycol, a polyethylene oxide and a
combination of a polyethylene glycol and a polyethylene oxide.
76. The method of claim 74, wherein the channeling agent has a
migration in compliance with at least one member selected from the
group consisting of: United States Pharmacopeia Standard 661
regarding physiochemical tests to plastics and heavy metals and
nonvolatile residue in polyethylene containers, European Union
Regulation No. 10/2011 of Jan. 14, 2011, and Notification No. 20 of
the Japanese Ministry of Welfare regarding food packaging and
containers.
77. The method of claim 74, wherein the channeling agent is a
propylene oxide polymerisate-monobutyl ether or a propylene oxide
polymerisate.
78. The method of claim 74, wherein the base polymer is
polypropylene present in an amount of 24% to 60%, the active agent
is a desiccant or an oxygen absorber present in an amount of 40% to
70%, and the channeling agent is a propylene oxide
polymerisate-monobutyl ether present in an amount of 2% to 10%.
79. A method of producing an entrained polymer, the entrained
polymer comprising a base polymer, an active agent that is
immiscible with the base polymer and acts on, interacts or reacts
with a selected material, and a channeling agent that is immiscible
with the base polymer and has an affinity to transmit a selected
material through the entrained polymer at a faster rate than in
solely the base polymer, wherein the channeling agent is a water
insoluble polymer, the method comprising: blending the channeling
agent and base polymer; heating the channeling agent and the base
polymer above the melting point of at least one of the channeling
agent or the base polymer to produce an entrained polymer mixture
in a molten state; cooling the entrained polymer mixture to
solidify; and immersing the solid entrained polymer in a solution
containing the active agent.
Description
CROSS REFERENCE
[0001] This application claims priority to U.S. Provisional
Application No. 61/783,029, filed Mar. 14, 2013. The entire
specification and all the drawings of the provisional application
is incorporated here by reference to provide continuity of
disclosure.
FIELD OF THE INVENTION
[0002] The invention pertains to channeling agents for entrained
polymers, entrained polymers including such channeling agents,
processes for producing entrained polymers, and products including
such entrained polymers.
BACKGROUND
[0003] The use of channeling agents, such as polyethylene glycol
(PEG) for channeling moisture, oxygen, or other materials, through
polymers, is known, and has been described in, for example U.S.
Pat. Nos. 5,911,937, 6,080,350, 6,124,006, 6,130,263, 6,194,079,
6,214,255, 6,486,231 and 7,005,459, each of which is incorporated
herein by reference as if fully set forth. Such channeling agents
may be incorporated into packaging by way of a polymeric sleeve,
insert, or package formed of the polymer itself. The polymeric
material containing the channeling agent is further entrained with
an active agent, for example, an absorbing or releasing material.
The channeling agent forms channels between the interior of package
and the active agent located interior to the polymer, to transmit a
selected material, which may be, for example a material absorbed or
released by the absorbing or releasing material.
[0004] Such polymers can be useful, for example, in packaging of
pharmaceuticals, nutraceuticals, medical devices, foodstuffs,
electronics and tobacco products. The entrained polymer, and as a
result, some of the channeling agent incorporated therein, will
contact the packaged material in these types of applications. As a
result, the use of a channeling agent that does not migrate into
the packaged product is desirable, so as to avoid contact with or
possible consumption of the channeling agent by the consumer. Such
a channeling agent may be, for example, a water insoluble polymer,
so that contact with moisture in the product does not cause
extraction of the channeling agent.
SUMMARY
[0005] Accordingly, in one aspect, the present invention is
directed to an entrained polymer that includes a base polymer, an
active agent and a channeling agent. The active agent is immiscible
with the base polymer and reacts with a selected material. The
channeling agent is a water insoluble polymer, is immiscible with
the base polymer, and has an affinity to transmit a selected
material through the entrained polymer at a faster rate than in
solely the base polymer.
[0006] In another aspect, the present invention is directed to an
entrained polymer that includes a base polymer, an active agent and
a channeling agent. The entrained polymer of this embodiment
results in substantially lower extractables than a reference
entrained polymer having a reference channeling agent in a weight
percentage substantially equivalent to that of the channeling
agent, wherein the reference channeling agent is a polyethylene
glycol and/or a polyethylene oxide.
[0007] In another aspect, the present invention is directed to
methods of producing entrained polymers.
[0008] In another aspect, the present invention is directed to
shaped articles formed of an entrained polymer.
[0009] In another aspect, the present invention is directed to
containers containing a shaped article formed of an entrained
polymer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view of an active plug formed of the
entrained polymer of the present invention;
[0011] FIG. 2 is a cross section taken along line 2-2 of FIG.
1;
[0012] FIG. 3 is a cross section similar to that of FIG. 2, showing
an active plug formed of another embodiment of an entrained polymer
according to the invention;
[0013] FIG. 4 is a cross section of an active container having an
active plug formed of an entrained polymer according to the
invention housed therein;
[0014] FIG. 5 is a cross section of an active container similar to
that of FIG. 4, in which the plug and the container are formed
integrally;
[0015] FIG. 6 is a cross section of an active container having a
liner formed of an entrained polymer according to the
invention;
[0016] FIG. 7 is a cross sectional view of an active sheet formed
of an entrained polymer according to the invention, affixed to a
barrier sheet;
[0017] FIG. 8 is a cross sectional view of an active sheet similar
to that of FIG. 7, formed integrally with a barrier sheet;
[0018] FIG. 9 is a cross section of an active package according to
the invention;
[0019] FIG. 10 is a schematic illustration of an entrained polymer
according to the invention, in which the active agent is a
releasing material; and
[0020] FIG. 11 is a schematic illustration of an entrained polymer
according to the invention, in which the active agent is an
absorbing material.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Detailed embodiments of the present invention are disclosed
herein, but it should be understood that the disclosed embodiments
are merely exemplary of the invention, which may be embodied in
various forms. The figures are not necessarily to scale; some
features may be exaggerated to show details of particular
components. Therefore, specific structural and functional details
disclosed herein are not to be interpreted as limiting, but merely
as a basis for the claims and as a representative basis for
teaching one skilled in the art to variously employ the present
invention.
[0022] As used herein, the term "active" is defined as capable of
acting on, interacting with or reacting with a selected material
according to the invention. Examples of such actions or
interactions may include absorption or release of the selected
material.
[0023] As used herein, the term "active agent" is defined as a
material that (1) is immiscible with the base polymer and when
mixed and heated with the base polymer and the channeling agent,
will not melt, i.e., has a melting point that is higher than the
melting point for either the base polymer or the channeling agent,
and (2) acts on, interacts or reacts with a selected material. The
term "active agent" may include but is not limited to materials
that absorb or release the selected material(s). Active agents
according to the invention may be in the form of particles, but the
invention should not be viewed as limited to particulate active
agents.
[0024] As used herein, the term "base polymer" is a polymer
optionally having a gas transmission rate of a selected material
that is substantially lower than, lower than or substantially
equivalent to, that of the channeling agent. By way of example,
such a transmission rate would be a water vapor transmission rate
in embodiments where the selected material is moisture and the
active agent is a water absorbing desiccant. The primary function
of the base polymer is to provide structure for the entrained
polymer.
[0025] Referring to such a comparison of the base polymer and
channeling agent water vapor transmission rate, in one embodiment,
the channeling agent has a water vapor transmission rate of at
least two times that of the base polymer. In another embodiment,
the channeling agent has a water vapor transmission rate of at
least five times that of the base polymer. In another embodiment,
the channeling agent has a water vapor transmission rate of at
least ten times that of the base polymer. In still another
embodiment, the channeling agent has a water vapor transmission
rate of at least twenty times that of the base polymer. In still
another embodiment, the channeling agent has a water vapor
transmission rate of at least fifty times that of the base polymer.
In still another embodiment, the channeling agent has a water vapor
transmission rate of at least one hundred times that of the base
polymer.
[0026] As used herein, the term "channeling agent" or "channeling
agents" is defined as a material that is immiscible with the base
polymer and has an affinity to transport a gas phase substance at a
faster rate than the base polymer. Optionally, a channeling agent
is capable of forming channels through the entrained polymer when
formed by mixing the channeling agent with the base polymer.
Optionally, such channels are capable of transmitting a selected
material through the entrained polymer at a faster rate than in
solely the base polymer.
[0027] As used herein, the term "channels" or "interconnecting
channels" is defined as passages formed of the channeling agent
that penetrate through the base polymer and may be interconnected
with each other.
[0028] As used herein, the term "entrained polymer" is defined as a
monolithic material formed of at least a base polymer with an
active agent and/or channeling agent entrained or distributed
throughout.
[0029] As used herein, the term "melting point" is defined as the
first order transition point of the material determined by
differential scanning calorimetry (DSC).
[0030] As used herein, the term "monolithic," "monolithic
structure" or "monolithic composition" is defined as a composition
or material that does not consist of two or more discrete
macroscopic layers or portions. Accordingly, a "monolithic
composition" does not include a multi-layer composite.
[0031] As used herein, the term "phase" is defined as a portion or
component of a monolithic structure or composition that is
uniformly distributed throughout, to give the structure or
composition it's monolithic characteristics.
[0032] As used herein, the term "selected material" is defined as a
material that is acted upon by, or interacts or reacts with an
active agent and is capable of being transmitted through the
channels of the entrained polymer. For example, in embodiments in
which a desiccant is used as an active agent, the selected material
may be moisture or a gas that can be absorbed by the desiccant. In
embodiments in which a releasing material is used as an active
agent, the selected material may be an agent released by the
releasing material, such as moisture, fragrance, or an
antimicrobial agent.
[0033] As used herein, the term "three phase" is defined as a
monolithic composition or structure comprising three or more
phases. An example of a three phase composition according to the
invention would be an entrained polymer formed of a base polymer,
active agent, and channeling agent. Optionally, a three phase
composition or structure may include an additional phase, e.g., a
colorant.
[0034] FIGS. 1-11 show schematic illustrations of entrained
polymers 10 and various packaging assemblies formed of entrained
polymers according to the invention. The entrained polymers 10 each
include a base polymer 25, a channeling agent 35 and an active
agent 30. As shown, the channeling agent 35 forms interconnecting
channels 45 through the entrained polymer 10. At least some of the
active agent 30 is contained within these channels 45, such that
the channels 45 communicate between the active agent 30 and the
exterior of the entrained polymer 10 via channel openings 48 formed
at outer surfaces of the entrained polymer 25. The active agent 30
can be, for example, any one of a variety or absorbing or releasing
materials, as described in further detail below.
[0035] The channeling agent 35 can be a polymer with a migration in
compliance with United States Pharmacopeia Standard 661 regarding
physiochemical tests to plastics and heavy metals and nonvolatile
residue in polyethylene containers, it being understood that the
tests outlined in this standard could be applied to containers made
of materials in accordance with the invention. In another
embodiment, the channeling agent 35 is a polymer with a migration
in compliance with European Union Commission Regulation (EU) No.
10/2011 of Jan. 14, 2011 on plastic materials and articles intended
to come into contact with food. In another embodiment, the
channeling agent 35 is a polymer with a migration in compliance
with Notification No. 20 of the Japanese Ministry of Welfare
regarding food packaging and containers. The channeling agent 35
can be, for example, a water insoluble polymer, such as a propylene
oxide polymerisate-monobutyl ether, such as Polyglykol B01/240,
produced by CLARIANT. In other embodiments, the channeling agent
could be a propylene oxide polymerisate monobutyl ether, such as
Polyglykol B01/20, produced by CLARIANT, propylene oxide
polymerisate, such as Polyglykol D01/240, produced by CLARIANT,
ethylene vinyl acetate, nylon 6, nylon 66, or any combination of
the foregoing.
[0036] Suitable active agents according to the invention include
absorbing materials, such as desiccating compounds. FIG. 11
illustrates an embodiment of an entrained polymer 10 according to
the invention, in which the active agent 30 is an absorbing
material. The arrows indicate the path of the selected material,
for example moisture or gas, from an exterior of the entrained
polymer 10, through the channels 45, to the particles of active
agent 30, which absorb the selected material.
[0037] Various types of absorbing materials or desiccating
compounds can be used as active agents in the entrained polymers of
the invention. The first type of desiccating compounds, hereinafter
referred to as "hydrate forming desiccants," comprises chemical
compounds that can combine with water to form hydrates. Examples of
hydrate forming desiccants are anhydrous salts which tend to absorb
water or moisture and form a stable hydrate. In this reaction with
the moisture, a stable compound is formed within which the moisture
is held and prevented from release by chemical interaction.
[0038] The second type of desiccating compounds, hereinafter
referred to as "reactive desiccants," are those which are
considered to be reactive. These compounds typically undergo a
chemical reaction with water or moisture and form new compounds
within which the water is combined. These newly formed compounds
are generally irreversible at low temperature and require a
significant amount of energy to be regenerated so that they may be
reused as desiccants. These reactive desiccants are mainly used in
solvent drying and as active agents to polymers which must
themselves be maintained in a moisture reduced state.
[0039] The third type of desiccating compounds, hereinafter
referred to as "physical absorption desiccants," obtain their
moisture absorbing capabilities through physical absorption. The
absorption process is accomplished because of a fine capillary
morphology of the desiccant particles, which pulls moisture
therethrough. The pore size of the capillaries, as well as the
capillaries' density, determine the absorption properties of the
desiccant. Examples of these physical absorption desiccants include
molecular sieve, silica gels, clays (e.g. montmorillimite clay),
certain synthetic polymers (e.g. those used in baby diapers), and
starches. Because these types of physical absorption desiccants are
both inert and non-water soluble, they are preferred for many
applications. Exemplary molecular sieve pore sizes that are
suitable for use in the present invention include between about 3
to 15 Angstroms; about 3 to 5 Angstroms, about 5 to 8:3 Angstroms;
4 Angstroms; 5 Angstroms; 8 Angstroms and 10 Angstroms. In another
exemplary embodiment, the pore size of silica gel is about 24
Angstroms. Among other reasons, these innocuous characteristics are
particularly compatible with food products and medicinal products
that may be enclosed within containers formed from the entrained
polymers, or at least exposed thereto. As stated previously,
however, any of the three types may be employed to form the
entrained polymers of the present invention.
[0040] Suitable absorbing materials may also include: (1) metals
and alloys such as, but not limited to, nickel, copper, aluminum,
silicon, solder, silver, gold; (2) metal-plated particulates such
as silver-plated copper, silver-placed nickel, silver-plated glass
microspheres; (3) inorganics such as BaTiO.sub.3, SrTiO.sub.3,
SiO.sub.2, Al.sub.2O.sub.3, ZnO, TiO.sub.2, MnO, CuO,
Sb.sub.2O.sub.3, WC, fused silica, fumed silica, amorphous fused
silica, sol-gel silica, sol-gel titanates, mixed titanates, ion
exchange resins, lithium-containing ceramics, hollow glass
microspheres; (4) carbon-based materials such as carbon, activated
charcoal, carbon black, ketchem black, diamond powder; and (5)
elastomers, such as polybutadiene, polysiloxane, and semi-metals,
ceramic and; (6) other fillers and pigments.
[0041] In another example, the absorbing material may be calcium
oxide. In the presence of moisture and carbon dioxide, the calcium
oxide is converted to calcium carbonate. Accordingly, calcium oxide
may be used as the absorbing material in applications where
absorption of carbon dioxide is needed. Such applications include
preserving fresh foods (e.g., fruits and vegetables) that give off
carbon dioxide.
[0042] In one embodiment relating to the absorbing material having
a relatively fine particle size, many small interconnecting
channels throughout the entrained polymer are produced by the
channeling agent, as opposed to a few large interconnecting
channels that will expose less surface area within the polymer.
Dimer agents such as polypropylene maleic anhydride, or any
plasticizer, may be optionally added to the mixture to reduce
viscosities and increase the mixing compatibility of the base
polymer and channeling agent, thereby increasing the dispersion of
the channels throughout the entrained polymer.
[0043] Other suitable active agents according to the invention
include releasing materials. FIG. 10 illustrates an embodiment of
an entrained polymer 10 according to the invention, in which the
active agent 30 is a releasing material. The arrows indicate the
path of the selected material, for example fragrance, from the
particles of active agent 10, through the channels 45, to an
exterior of the entrained polymer 10.
[0044] A variety of releasing materials could be employed as active
agents in the entrained polymers of the present invention. Such
materials may comprise any suitable material that will release the
selected material from the releasing material. The selected
material released from the releasing material could be in the form
of a solid, gel, liquid or gas. These substances can perform a
variety of functions including: serving as a fragrance, flavor, or
perfume source; supplying a biologically active ingredient such as
pesticide, pest repellent, antimicrobials, bait, aromatic
medicines, etc.; providing humidifying or desiccating substances;
delivering air-borne active chemicals, such as corrosion
inhibitors; ripening agents and odor-making agents.
[0045] Suitable biocides for use as releasing materials in the
entrained polymers of the present invention may include, but are
not limited to, pesticides, herbicides, nematacides, fungicides,
rodenticides and/or mixtures thereof. In addition to the biocides,
the covering of the present invention can also release nutrients,
plant growth regulators, pheromones, defoliants and/or mixture
thereof.
[0046] Quaternary ammonium compounds can also be used as releasing
materials according to the invention. Such compounds not only
function as surfactants, but also impart to the surface of the
entrained polymer aseptic properties or establish conditions for
reducing the number of microbial organisms, some of which can be
pathogenic. Numerous other antimicrobial agents, such as
benzalkonium chloride and related types of compounds as
hexachlorophene, may also be used as releasing agents according to
the invention.
[0047] Other potential releasing materials include fragrances,
including natural, essential oils and synthetic perfumes, and
blends thereof. Typical perfumery materials which may form part of,
or possibly the whole of, the active ingredient include: natural
essential oils such as lemon oil, mandarin oil, clove leaf oil,
petitgrain oil, cedar wood oil, patchouli oil, lavandin oil, neroli
oil, ylang oil, rose absolute or jasmin absolute; natural resins
such as labdanum resin or olibanum resin; single perfumery
chemicals which may be isolated from natural sources or
manufactured synthetically, as for example alcohols such as
geraniol, nerol, citronellol, linalol, tetrahydrogeraniol,
betaphenylethyl alcohol, methyl phenyl carbinol, dimethyl benzyl
carbinol, menthol or cedrol; acetates and other esters derived from
such alcohols-aldehydes such as citral, citronellal,
hydroxycitronellal, lauric aldehyde, undecylenic aldehyde,
cinnamaldehyde, amyl cinnamic aldehyde, vanillin or heliotropin;
acetals derived from such aldehydes; ketones such as methyl hexyl
ketone, the ionones and methylionones; phenolic compounds such as
eugenol and isoeugenol; synthetic musks such as musk xylene, musk
ketone and ethylene brassylate.
[0048] In some embodiments, the active agent has a polarity that
causes an affinity between the active agent and the channeling
agent. An example of such a polar active agent is silica, an
absorbing agent that is more compatible with the channeling agent
than it is typically with the base polymer. For this reason, during
the separating process when the interconnecting channels are formed
throughout the entrained polymer, the active agent will congregate
toward the channeling agent domains to which it has a greater
affinity. In this manner, the channeling agent is permitted to act
as a bridge between the vapor located exteriorly to the entrained
polymer and the active agent that is located within the entrained
polymer. This is particularly true with respect to active agent
that is bound within the channeling agent filled passages. In a
further embodiment, polar plasticizers such as glycerin may be
further added to the mixture, in order to enhance the dispersion or
mixing of the active agent into the channeling agent.
[0049] It is believed that the higher the active agent
concentration in the mixture, the greater the absorption capacity
will be of the final composition. However, too high an active agent
concentration could cause the entrained polymer to be more brittle
and the molten mixture of active agent, base polymer and channeling
agent to be more difficult to either thermally form, extrude or
injection mold. In one embodiment, the active agent loading level
can range from 10% to 80%, preferably 40% to 70%, more preferably
from 50% to 70%, and even more preferably from 55% to 65% by weight
with respect to the total weight of the entrained polymer.
[0050] In one embodiment, the base polymer of the present invention
may be a thermoplastic material. Examples of suitable thermoplastic
materials include polyolefins such as polypropylene and
polyethylene, polyisoprene, polybutadiene, polybutene,
polysiloxane, polycarbonates, polyamides, ethylene-vinyl acetate
copolymers, ethylene-methacrylate copolymer, poly(vinyl chloride),
polystyrene, polyesters, polyanhydrides, polyacrylianitrile,
polysulfones, polyacrylic ester, acrylic, polyurethane and
polyacetal, or copolymers or mixtures thereof.
[0051] In some embodiments, because the entrained polymer 10 of the
present invention may be more brittle than other polymeric
materials, due to the inclusion of an active agent 30, a package
may be molded so that an interior portion of the package is formed
of an entrained polymer 10 of the present invention, while the
exterior portions are formed from pure polymer or a composition of
the present invention with a lower proportion of active agent 30.
For example, a package having an interior portion composed of an
entrained polymer 10 the present invention and an exterior portion
composed of pure polymer, will typically not only be more durable
and less brittle, but the pure polymer exterior portion can also
act as a vapor barrier that resists the transmission of undesirable
vapors from the exterior into the interior of the package. In this
manner, the absorption capacity of the absorbing agent 30 is
potentiated by exposing it exclusively to the interior of the
package from which it is desired that the vapor be withdrawn and
retained from.
[0052] The entrained polymer 10 of the present invention has
numerous applications. One exemplary application is the
construction of rigid containers 61, which are suitable for
containing relatively small volumes of product such as foodstuffs
and medicines. In many cases, these types of products must be
shipped and stored in controlled environments (e.g., reduced
moisture and/or oxygen). In an embodiment, the entrained polymer 10
of the present invention may be formed into an insert for inclusion
within the interior of the container 61. An example of one form of
an insert is a plug 55 of any suitable shape, such as that shown in
FIGS. 4 and 5. While the plug 55 would serve its purpose by being
merely deposited within the container, it may also be fixed to an
interior location so that it does move about within the interior
space. The plug 55 may be formed into a disc that is shaped and
sized to be press fitted snugly into a receiving location at the
bottom of a polymeric container 61, as shown in FIGS. 4 and 5.
[0053] In other embodiments, a liner 70 may be formed from the
entrained polymer 10 of the present invention, which has an
exterior surface substantially conforming to an interior surface of
the container body 60 Like the plug 55 described above, the liner
70 may be sized so as to be press-fit into position within the
container body 60 where it is held sufficiently snugly to prevent
unintended disengagement therefrom. Alternatively, either the plug
55 or liner 70 may be initially constructed and allowed to harden,
and then the container body 60 subsequently constructed thereabout
so that the greater shrinkage characteristics of the polymeric
container body 60 not containing entrained polymer, cause the
container body 60 to tightly shrink fit about the plug 55 or liner
70 so that neither becomes easily disengaged from the other. In
still a further embodiment, the insert taking the form of either a
plug 55 or a liner 70 may be simultaneously co-molded with the
container body 60 so that each is integrally joined with the other.
In embodiments formed by way of such co-molding, the viscosities of
the entrained polymer 10 insert and the container body 60 may be
approximately equal to facilitate the proper and desired location
of the two phases of liquid or molten material that are molded
together.
[0054] In yet another embodiment, entrained polymer 10 of the
present invention may be used to form an entrained polymer sheet 75
that is joined with another sheet 80. The sheets 75, 80 are
effectively laminated one to the other so that sheet 80 can form a
substantially gas impermeable exterior layer. The laminate of
sheets 75, 80 may then be used to wrap an item which is to be
stored in a controlled environment. Sheets 75, 80 could be joined
by, for example, thermal extrusion.
[0055] Methods of producing entrained polymers 10 according to the
present invention include blending a base polymer 25 and a
channeling agent 35. The active agent 30 is blended into the base
polymer 25 either before or after adding the channeling agent 35.
All three components are uniformly distributed within the entrained
polymer 10 mixture.
[0056] Embodiments of entrained polymers 10 according to the
invention may be formed as follows: [0057] a. The active agent 30
and channeling agent 35 are added to the base polymer 25 when the
base polymer 25 is above its melting point and in a molten state.
The channeling agent 35 may also be above its melting point and in
a molten state at this time. [0058] b. The molten base polymer 25,
active agent 30 and channeling agent 35 are blended and thoroughly
mixed to uniformity.
[0059] Other embodiments of entrained polymers 10 according to the
invention may be formed as follows: [0060] a. The active agent 30
and channeling agent 35 are added to the base polymer 25 prior to
the base polymer 25 reaching its melting point and going into a
molten state. The channeling agent 35 may also be in a pre-molten
state, prior to reaching its melting point at this time. The
mixture of active agent 30, channeling agent 35 and base polymer 35
may be a powder at this time. [0061] b. The base polymer 25, active
agent 30 and channeling agent 35 are blended and thoroughly mixed
to uniformity. [0062] c. The mixture is heated until it reaches the
melting point of one or both of the channeling agent 35 and base
polymer 25, producing a molten state.
[0063] Other embodiments of entrained polymers according to the
invention may be formed as follows: [0064] a. The channeling agent
35 and base polymer 25 are mixed when the base polymer 25 is above
its melting point and in a molten state. The channeling agent 35
may also be above its melting point and in a molten state. [0065]
b. The active agent 30 is then added to the channeling agent 35 and
base polymer 25 mixture. [0066] c. The molten base polymer 25,
active agent 30 and channeling agent 35 are blended and thoroughly
mixed to uniformity.
[0067] Other embodiments of entrained polymers 10 according to the
invention may be formed as follows: [0068] a. The channeling agent
35 and base polymer 25 are mixed prior to the base polymer 25
reaching its melting point and going into a molten state. The
channeling agent 35 may also be in a pre-molten state, prior to
reaching its melting point, at this time. [0069] b. The active
agent 30 is then added to the channeling agent 35 and base polymer
25 mixture. [0070] c. The base polymer 25, active agent 30 and
channeling agent 35 are blended and thoroughly mixed to uniformity.
[0071] d. The mixture is heated until it reaches the melting point
of one or both of the base polymer 25 and channeling agent 35, and
goes into a molten state.
[0072] Other embodiments of entrained polymers according to the
invention can be formed as follows: [0073] a. The channeling agent
35 and base polymer 25 are blended either in a molten state, above
the melting point of the base polymer, or in a pre-molten state,
prior to reaching the melting point of the base polymer. [0074] b.
If blended in a pre-molten state, the mixture is heated above the
melting point of the base polymer. [0075] c. The mixture is cooled
to solidify. [0076] d. The mixture is immersed in a solution
containing the active agent.
[0077] In the foregoing example, the active agent 30 is taken up by
the composition of base polymer 25 and active agent 35, to form a
monolithic composition consisting of at least three phases
including the base polymer 25, the channeling agent 35, and the
active agent 30. It should be understood that, for purposes of the
present invention, immersing includes soaking, coating or other
methods that result in an uptake of the active agent 30 by the
composition of base polymer 25 and channeling agent 35. This
embodiment may be well-suited for materials that are heat-sensitive
and thus, that may not be capable of withstanding the temperatures
required to melt the channeling agent 35 during processing. Such
high temperatures may include, for example, the temperatures
incurred during extrusion, which may occur during step d.
Consequently, the active agent 30 may be added after extrusion and
thus, not subject to high extrusion temperatures, which may
detrimentally affect the active agent 30. A further example of this
embodiment relates to producing the solution for the active agent
30. In one embodiment, an aqueous solution of the active agent 30
is produced.
[0078] After thorough blending and processing as described above,
the entrained polymer 30 is cooled, may be formed into a shaped
article such as a plug 55 or liner 70, and the channeling agent 35
forms interconnecting channels that act as transmission
communicating passages, through which a selected material, such as
moisture, oxygen or odor, is transmitted through the entrained
polymer 30 between the active agent 30 and the exterior thereof.
The entrained polymer 30 may be monolithic, with the base polymer
25, active agent 30 and channeling agent 35 forming a three phase
system.
[0079] In some embodiments, the components are first dry mixed in a
mixer such as a HENSCHEL mixer, and then fed to a compounder. A
LEISTRITZ twin screw extruder, for example, or a WERNER PFLEIDER
mixer can be used to achieve a good melt mix at about 140 C to
about 170 C. The melt can then be either extruded to form, for
example, a film or converted into pellets using dry air cooling on
a vibrating conveyer. Where pellets containing channels are formed,
they can, for example, then be either injection molded into beads,
sieves, or co-injected with polypropylene as the inside layer of a
container.
[0080] In an embodiment of the present invention, the base polymer
25 may be a water insoluble polymer such as polypropylene maleic
anhydride, which may be combined with the channeling agent 35
without the active agent 30. In this embodiment, the maleic
anhydride may cause this composition to behave in a similar manner
as the three phase system of the present invention, containing
interconnecting channels. In another embodiment, an active agent
could also be added to the composition described in this
paragraph.
[0081] In an embodiment, after the entrained polymer 10 of the
present invention is produced, some or all of the channeling agent
35 could be removed by conventional means such as, leaching. The
resulting entrained polymer 10 may then be capable of transmitting
a higher amount of the desired material therethrough.
Alternatively, the resulting entrained polymer 10 may then be
immersed in a solution containing a desired material and further
processed as desired above.
[0082] In some embodiments, the entrained polymer 10 of the present
invention is used to form a plug 55 for inclusion within a
container 61 constructed of a barrier substance. In other
embodiments, the entrained polymer 10 of the present invention is
used to form a liner 70 for inclusion within a container 61
constructed from a barrier substance. In other embodiments, the
entrained polymer 10 of the present invention is used to form an
absorption sheet 75. The absorption sheet 75 may optionally be
combined with a barrier sheet 80 constructed of a barrier substance
for use as a packaging wrap. In other embodiments, the entrained
polymer 10 of the present invention is used to form an active
insert 20 for a container 61.
[0083] Referring to FIG. 1, an insert 20, constructed from the
entrained polymer of the present invention is illustrated. The
insert 20 is in the form of a plug 55 that may be deposited into a
container body 60 (FIG. 5) thereby establishing an active container
61. The container body 60 could be constructed of a barrier
substance, for example a gas or moisture impermeable material,
which blocks transmission of the selected material therethrough. In
such an embodiment, the selected material could be a material to
which contact with the product container in the container 61 is
undesirable, and the active agent could be an absorbing agent. The
combination of the barrier substance container and the active plug
minimizes the amount of the selected material within the container
60. In another embodiment, the selected material is a material
released by the active agent, which is a releasing material, and
the container body is formed of a barrier substance, to help trap
the selected material released by the active agent within the
container.
[0084] A container according to the invention, such as a container
formed of a barrier substance as described above, could be molded
about the plug 55 so that at least a portion of the plug is exposed
to the interior of the container. In another embodiment, the plug
55 is co-molded with the container body 60 so that at least a
portion of the plug 55 is exposed to the interior of the container
61.
[0085] Referring to FIG. 2, a cross-sectional view is shown of the
plug 55 that has been constructed from an entrained polymer 10
comprising the base polymer 25 that has been uniformly blended with
the active agent 30 and the hydrophilic agent 35. In the
illustration of FIG. 2, the entrained polymer of the present
invention has been solidified so that interconnecting channels 45
have formed throughout the entrained polymer 10 to establish
passages throughout the solidified plug 55. As may be appreciated
from both FIGS. 1 and 2, the passages terminate in channel openings
48 at exterior surfaces of the plug 55.
[0086] FIG. 3 illustrates the embodiment of a plug 55 similar in
construction and makeup to the plug 55 of FIG. 2, where
interconnecting channels 45 are very fine compared to those of FIG.
2. This can result from the use of a dimer agent (i.e., a
plasticizer) together with a channeling agent 35. The dimer agent
may enhance the compatibility between the base polymer 25 and the
channeling agent 35. This enhanced compatibility is facilitated by
a lowered viscosity of the blend, which may promote a more thorough
blending of the base polymer 25 and channeling agent 35, which
under normal conditions can resist combination into a uniform
solution. Upon solidification of the entrained polymer 10 having a
dimer agent added thereto, the interconnecting channels 45 which
are formed therethrough have a greater dispersion and a smaller
porosity, thereby establishing a greater density of interconnecting
channels throughout the plug 55.
[0087] Interconnecting channels 45, such as those disclosed herein,
facilitate transmission of a desired material, such as moisture,
gas or odor, through the base polymer 25, which generally resists
permeation of these materials, thus acting as a barrier thereto.
For this reason, the base polymer 25 itself acts as a barrier
substance within which an active agent 30 may be entrained. The
interconnecting channels 45 formed of the channeling agent 35
provide pathways for the desired material to move through the
entrained polymer 10. Without these interconnecting channels 45, it
is believed that relatively small quantities of the desired
material would be transmitted through the base polymer 25 to or
from the active agent 30. In the case in which the desired material
is transmitted to the active agent 30, it may be absorbed by the
active agent 30, for example in embodiments in which the active
agent 30 is an active agent such as a desiccant or an oxygen
absorber. In the case in which the desired material is transmitted
from the active agent 30, it may be released from the active agent
30, for example in embodiments in which the active agent 30 is a
releasing material, such as a fragrance or gas releasing
material.
[0088] FIG. 4 illustrates an embodiment of the present invention of
a plug 55 which has been deposited into a container body 60,
thereby establishing an active container 61. The container body 60
has an interior surface 65 and a plug 55 is affixed thereto, which
is constructed substantially from the entrained polymer 10 of the
present invention. The container body 60 may be formed of a
polymeric or other material that is substantially impermeable to
the material transmitted by the interconnecting channels 48 of the
entrained polymer 10. For example, the container body 60 could be
formed of the same material as that used for the base polymer 25 of
the entrained polymer 10. In this manner, the transmitted material
is resisted from being transmitted across the walls of the
container 61 when the container 61 is closed. As may be seen in
FIG. 4, the plug 55 has been press fit into a bottom region of the
container 61. It is contemplated that the plug 55 may be merely
deposited in the container 61 for loose containment therein, or
coupled to the body of the container 61 in a manner that fixes the
plug 55 to the container 61. The coupling between the plug 55 and
the container 61 is intended to prevent the dislocation and
relative movement of the plug 55 within the container 61. This
connection may be accomplished by a snug press fit between the plug
55 and the interior surface 65 of the container body 60, or a
mechanical connection such as adhesives, prongs, lips or ridges
that extend about the plug 55 to hold the plug 55 in place. In yet
another embodiment, it is contemplated that the container body 60
may be molded about the plug 55 so that during the curing process
of the container body 60, container the body 60 shrinks about the
plug 55, thereby causing a shrink-fit to be established between the
two components. This type of coupling may also be accomplished in a
co-molding process or sequential molding process, in which the plug
55 will have less shrinkage than the polymer 25 comprised container
body 60.
[0089] FIG. 5 illustrates an active container 61 having the
entrained polymer of the present invention formed of a plug 55
located at a bottom location of the container 60, similar to the
configuration illustrated in FIG. 4, but differing in that the plug
55 and container body 60 are co-molded so that a unified body 61 is
formed with a less distinct interface between the plug 55 and
container body 60 components.
[0090] FIG. 6 illustrates a concept similar to those of FIGS. 4 and
5, in which the proportions of the plug 55 have been extended so
that a liner 70 is formed which covers a greater portion of the
interior surface 65 of the desiccating container 61. The liner 70
is not localized in the bottom portion of the container body 60,
but instead has walls that extend upwardly and cover portions of
the walls of the container 61. In such an embodiment, the container
body 60 could be formed of a barrier substance, as described above.
The container body 60 could be molded about the plug liner 70, or
the liner 70 and container body 60 could be co-molded, as described
above.
[0091] In another embodiment, a liner 70 may be formed from the
entrained polymer 10 and then be included within a container 60
constructed from a barrier substance. The liner 70 typically, but
not necessarily, has an exterior surface configured for mating
engagement with an interior surface 65 of the container 60. The
liner 70 may be pressed into mating engagement with the container
60 so that a container 61 is created wherein at least a majority of
the interior surface 65 of the container 61 is covered by the liner
70. The liner 70 may be formed from the entrained polymer and then
a container 60 constructed from a barrier substance may be molded
about the liner 70 so that at least a portion of the liner 70 is
exposed to an interior of the container 60 and a majority of an
interior surface 65 of the container 60 is covered by the liner
70.
[0092] FIGS. 7 and 8 illustrate embodiments of the invention in
which an active sheet 75 formed of the entrained polymer 10 of the
invention is used in combination with a barrier sheet 80. The
characteristics of the active sheet 75 are similar to those
described with respect to the plug 55 and liner 70 and container
body 60, while the characteristics of the barrier sheet 80 may be
similar to the characteristics of the container body 60 described
above. Specifically, FIG. 7 illustrates an embodiment in which the
two sheets 75, 80 are separately molded, and later combined to form
a packaging wrap having active characteristics at an interior
surface formed by the entrained polymer 10 active sheet 75, and
vapor resistant characteristics at an exterior surface formed by
the barrier sheet 80.
[0093] FIG. 8 illustrates a co-molded arrangement in which an
interface between the active sheet 75 and the barrier sheet 80 is
less distinct than in the embodiment of FIG. 7. This product can be
produced by a thermal forming process. In such a process, the
barrier sheet 80 layer is melted and partially formed into a sheet
with the active sheet 75 being deposited on top of the barrier
sheet 80 just prior to being pressed or extruded through a
slit-like opening in a thermal forming machine.
[0094] A laminate structure such as that shown in FIGS. 7 and 8
could also be formed by, for example, suction vacuum molding the
barrier sheet 80 with the active sheet 75.
[0095] It is also contemplated that the separate sheets 75, 80 of
FIG. 7 may be joined together with an adhesive or other suitable
means to form a laminate from the plurality of sheets 75, 80.
Alternatively, the sheets 75, 80 may be manufactured from a thermal
extrusion process whereby both sheets 75, 80 are manufactured at
the same time and effectively co-molded together to form the
embodiment illustrated in FIG. 8.
[0096] In one embodiment, the sheets of FIG. 7 or 8 are joined
together to form an active package 85, as shown in FIG. 9. As
shown, two laminates are provided, each formed of an active sheet
75 joined with a barrier sheet 80. The sheet laminates are stacked,
with the active sheets 75 facing one another, so as to be disposed
on an interior of the package, and are joined at a sealing region
90, formed about a perimeter of the sealed region of the package
interior. The sheets may be affixed by adhesives, heat sealing, or
other means known in the art.
[0097] The present invention will be illustrated in greater detail
by the following specific examples. It is understood that these
examples are given by way of illustration and are not meant to
limit the disclosure or claims. For example, although specific
relative humidity and temperature values may be provided, the
entrained polymer of the present invention is also suited for other
conditions. Moreover, these examples are meant to further
demonstrate that the present invention has interconnecting channels
and that the channeling agents reside in the interconnecting
channels. All percentages in the examples or elsewhere in the
specification are by weight unless otherwise specified.
EXAMPLE 1
[0098] The purpose of the following example is to demonstrate that
the entrained polymer of the present invention has interconnecting
channels by subjecting films made of the following materials to
moisture adsorption testing.
[0099] The following samples were prepared:
TABLE-US-00001 Raw Material Ratio Formulation Raw Material Function
(% weight) 1 Molecular Sieve 4A Active Agent 69 PEG 4,000
Channeling Agent 5 Basel HP548N Base Polymer 24 Colorant Polyone
3113 Colorant 2 2 Molecular Sieve 4A Active Agent 69 PEG 20,000
Channeling Agent 5 Basel HP548N Base Polymer 24 Colorant Polyone
3113 Colorant 2 3 Molecular Sieve 4A Active Agent 69 Lutrol PEO
Channeling Agent 5 Basel HP548N Base Polymer 24 Colorant Polyone
3113 Colorant 2 4 Molecular Sieve 4A Active Agent 69 Polyglykol
B01/240 Channeling Agent 5 Basel HP548N Base Polymer 24 Colorant
Polyone 3113 Colorant 2 5 Molecular Sieve 4A Active Agent 69 Basel
HP548N Base Polymer 29 Colorant Polyone 3113 Colorant 2
[0100] In each of the samples listed above, molecular sieve having
an aperture size of 4A was used as the active agent. Molecular
sieve is a moisture and gas absorbing material, which in the case
of the materials below, would absorb moisture or gas transmitted
through any channels formed in the material. Each sample contains
69% active agent.
[0101] Samples 1, 2, 3 and 4 each contain 5% channeling agent.
Sample 1 contains PEG 4,000, a polyethylene glycol, which is a
channeling agent known in the art. Sample 2 contains PEG 20,000, a
polyethylene glycol, which is a channeling agent known in the art.
Sample 3 contains Lutrol polyethylene oxide, which is a channeling
agent known in the art. Sample 4 contains Polyglykol B01/240, made
by CLARIANT, which is a propylene oxide polymerisate-monobutyl
ether, which is a channeling agent according to the invention.
Sample 5 is a control sample and contains no channeling agent.
[0102] Samples 1, 2, 3 and 4 each contain 24% Basel HP548N, a
polypropylene, as a base polymer. Sample 5 contains 29% Basel
HP548N, a polypropylene, as a base polymer.
[0103] Each of the samples contains 2% Colorant Polyone 3113.
Moisture Absorption Testing
Procedure
[0104] Each of the samples was subjected to moisture adsorption
testing using the following procedure: [0105] a. Parts were
accurately weighed on either an analytical or microbalance to
determine initial sample weight. [0106] b. Samples were placed into
an environmental chamber set to 22 C and 80% relative humidity and
allowed to absorb moisture over time. [0107] c. The samples were
re-weighed on a daily basis until no weight gain was measured for
three (3) consecutive days. The weights were recorded each day to
generate the results graph, shown below.
Results
[0108] The results of the Moisture Uptake Testing are summarized in
Table 1.
Discussion
[0109] As shown in Table 1, Sample 4, which includes a channeling
agent according to the invention, exhibits greater moisture
adsorption capabilities during the first 100 hours of testing, when
compared with other samples having the same composition, but with
known channeling agents. After 100 hours, the moisture adsorption
of Sample 4 slows and then levels off, but the total moisture
capacity of Sample 4 after 250 hours of testing is comparable to
that of samples using known channeling agents. It is thus believed
that propylene oxide polymerisate-monobutyl ether is at least as
effective a channeling agent as the polyethylene glycols and
polyethylene oxides known in the art. The absorption and capacity
of all samples having channeling agents are substantially greater
than that of control Sample 5, demonstrating the effectiveness of
channeling agents in facilitating moisture absorption. It is
believed that the enhanced absorption properties are attributable
to moisture being transmitted via channels formed by the channeling
agent, which penetrate the base polymer and connect the active
agent, in this case molecular sieve desiccant, with the sample
exterior.
Extractable Testing
Procedure
[0110] Extractable testing was performed in accordance with US
Pharmacopoeia standard 661.
Results
[0111] The results of extractable testing are summarized in Table
2.
TABLE-US-00002 TABLE 2 Weight loss of samples during USP 661
Extractable Testing Formulation Weight loss (g) Sample 2 0.020686
Sample 3 0.02123 Sample 4 0.00805
Discussion
[0112] As shown in Table 2, the weight loss values found by USP 661
extractable testing of Sample 4, which includes a channeling agent
according to the invention, is substantially lower than that of
Samples 2 and 3, indicating much lower extractable levels in Sample
4. One possible explanation is the hydrophilic nature of the known
channeling agents used in Samples 2 and 3. In contrast, the
propylene oxide polymerisate-monobutyl ether is not hydrophilic,
and therefore less likely to be extracted from the entrained
polymer when exposed to moisture. It is believed that the 0.00805 g
of weight loss that does occur in testing of Sample 4 may be
attributable to loss of molecular sieve, which is the active agent
used in this formulation. Accordingly, the use of a nonextractable
active agent in conjunction with the channeling agent of Sample 4
could potentially give rise to a formulation with no
extractables.
[0113] Thus in one aspect, the present invention is directed to an
entrained polymer that results in substantially lower (optionally
at least 1.5 times lower, optionally at least 2 times lower,
optionally at least 2.5 times lower, optionally at least 3 times
lower, optionally from 1.5 times lower to 3 times lower, optionally
from 2 times lower to 3 times lower) extractables than a reference
entrained polymer having a reference channeling agent in a weight
percentage substantially equivalent to that of the channeling
agent, wherein the reference channeling agent is selected from the
group consisting of a polyethylene glycol, a polyethylene oxide and
a combination of a polyethylene glycol and a polyethylene
oxide.
[0114] Monolithic compositions and their constituent compounds have
been described herein. As previously stated, detailed embodiments
of the present invention are disclosed herein; however, it is to be
understood that the disclosed embodiments are merely exemplary of
the invention that may be embodied in various forms. It will be
appreciated that many modifications and other variations that will
be appreciated by those skilled in the art are within the intended
scope of this invention as claimed below without departing from the
teachings, spirit and intended scope of the invention.
* * * * *