U.S. patent application number 14/070796 was filed with the patent office on 2014-07-31 for play composition including crosslinkable binder.
This patent application is currently assigned to Mattel, Inc.. The applicant listed for this patent is Abimael CORDOVA. Invention is credited to Abimael CORDOVA.
Application Number | 20140209835 14/070796 |
Document ID | / |
Family ID | 46162821 |
Filed Date | 2014-07-31 |
United States Patent
Application |
20140209835 |
Kind Code |
A1 |
CORDOVA; Abimael |
July 31, 2014 |
Play Composition Including Crosslinkable Binder
Abstract
The present invention is directed toward water based play
compositions including a crosslinkable network polymer and a
crosslinking system effective to crosslink the polymer. The
crosslinking system is a water-soluble salt complex including a
primary crosslinking agent, a secondary crosslinking agent, and a
tertiary crosslinking agent. The crosslinking system contains a
diminished amount of boron compounds while remaining effective in
crosslinking network polymers including polyvinyl alcohol (to form
moldable dough compositions) and guar gum (to form hydrogels).
Inventors: |
CORDOVA; Abimael; (La
Mirada, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CORDOVA; Abimael |
La Mirada |
CA |
US |
|
|
Assignee: |
Mattel, Inc.
El Segundo
CA
|
Family ID: |
46162821 |
Appl. No.: |
14/070796 |
Filed: |
November 4, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12957721 |
Dec 1, 2010 |
8603236 |
|
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14070796 |
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Current U.S.
Class: |
252/182.14 ;
106/205.01; 106/205.2; 106/205.31; 523/105 |
Current CPC
Class: |
C08K 13/02 20130101;
C08L 1/284 20130101; C08L 29/04 20130101; C08K 3/26 20130101; C08K
3/38 20130101; C08K 2201/014 20130101; C08K 3/26 20130101; C08K
2003/387 20130101; C08K 3/32 20130101; C08L 29/04 20130101; C08L
29/04 20130101; C08K 3/38 20130101; C08K 2003/262 20130101; C08K
2003/324 20130101 |
Class at
Publication: |
252/182.14 ;
523/105; 106/205.01; 106/205.31; 106/205.2 |
International
Class: |
C08K 3/26 20060101
C08K003/26; C08K 13/02 20060101 C08K013/02; C08K 3/38 20060101
C08K003/38; C08L 29/04 20060101 C08L029/04; C08K 3/32 20060101
C08K003/32 |
Claims
1. A flowable play gel composition comprising: water; a binder; and
a crosslinking system to crosslink the binder, the crosslinking
system comprising: a primary crosslinking agent comprising a first
alkali metal salt, and a secondary crosslinking agent comprising a
second alkali metal salt, wherein the crosslinking density
generated in the binder by the secondary crosslinking agent is less
than the crosslinking density generated in the binder by the
primary crosslinking agent, and a tertiary crosslinking agent that
is present in an amount of about 0.50% or less by weight of the gel
composition; wherein the crosslinking system and the binder
cooperate to form a hydrogel including a polymer network expanded
throughout its volume by the water.
2. The flowable play gel composition of claim 1, wherein the binder
is guar gum.
3. The flowable play gel of claim 2, wherein the tertiary
crosslinking agent comprises a borate salt.
4. The flowable play gel of claim 3, wherein the tertiary
crosslinking agent is present in an amount of about 0.10% or less
by weight of the gel composition.
5. The flowable play gel of claim 2, wherein: the primary
crosslinking agent is a phosphoric acid salt; the secondary
crosslinking agent is a carbonic acid salt; and the tertiary
crosslinking agent is a boric acid salt.
6. The flowable play gel composition of claim 5, wherein: the
primary crosslinking agent is disodium hydrogen phosphate; the
secondary crosslinking agent is sodium carbonate; and the tertiary
crosslinking agent is sodium tetraborate.
7. The flowable play gel composition of claim 2, wherein: the water
is present in a range of about 75% to about 95% by weight of the
gel composition; the guar gum binder is present in a range of about
0.50% to about 3% by weight of the gel composition; and the
crosslinking system is present in a range of about 0.10% to about
2.5 wt % by weight of the gel composition.
8. The flowable play gel composition of claim 7, wherein: the
primary crosslinking agent is present within the gel composition in
an amount of about 0.10 wt % to about 1.5 wt %; the secondary
crosslinking agent is present within the composition in an amount
of from about 0.01 wt % to about 0.50 wt %; and the tertiary
crosslinking agent is present within the composition in an amount
of from about 0.005 wt% to about 0.50 wt %.
9. The flowable composition of claim 2, wherein: the guar gum is
carboxylmethyl hydroxypropyl guar; the cross-linking system
comprises: disodium hydrogen phosphate, sodium carbonate, and
sodium tetraborate; and the water is present within the composition
in an amount of from about 75 wt % to about 95 wt %, the guar gum
is present within the composition in an amount of from about 0.50
wt % to about 3 wt %, and crosslinking system is present within the
composition in an amount of from about 0.1 wt % to about 2.5 wt
%.
10. The flowable play gel composition of claim 1, wherein the
crosslinking system is present within in a range of from about
0.10% to about 2.5% by weight of the gel composition.
11. A moldable dough composition comprising: water; a binder; and a
crosslinking system to crosslink the binder, the crosslinking
system comprising: a primary crosslinking agent comprising a first
alkali metal salt, wherein the primary crosslinking agent generates
a first crosslink density in the binder, and a secondary
crosslinking agent comprising a second alkali metal salt, wherein
the secondary crosslinking agent generates a second crosslink
density in the binder, and a tertiary crosslinking agent that is
present within the composition in an amount of 0.50 wt % or less,
wherein the first crosslink density generated by the first
crosslinking agent is greater than the second crosslink density
generated by the secondary crosslinking agent.
12. The moldable dough composition of claim 10, wherein: the binder
comprises polyvinyl alcohol; and the dough composition further
comprises a diol compound.
13. The moldable dough composition of claim 12, wherein: the water
is present in an amount of about 25% to about 75% by weight of the
dough composition; the polyvinyl alcohol is present in an amount of
about 4% to about 15% by weight of the dough composition; and the
diol compound is present in an amount of about 2% to about 10% by
weight of the dough composition.
14. The moldable dough composition of claim 12 further comprising a
thickener present in an amount of about 0.30% to about 1.5% by
weight of the dough composition.
15. The moldable dough composition of claim 11, wherein: the
primary crosslinking agent is potassium bicarbonate; the secondary
crosslinking agent is sodium carbonate; and the tertiary
crosslinking agent is sodium tetraborate.
16. The moldable dough composition of claim 15, wherein the
crosslinking system is present in an amount of about 0.45% to about
4.0% by weight of the dough composition.
17. The moldable dough composition of claim 11, wherein: the
primary crosslinking agent is present within the composition in an
amount of from about 0.5 wt% to about 3 wt %; the secondary
crosslinking agent is present within the composition in an amount
of from about 0.10 wt % to about 0.80 wt %; and the tertiary
crosslinking agent is present within the composition in an amount
of from about 0.005 wt% to about 0.50 wt %.
18. A crosslinking system to crosslink a polymeric binder within a
play composition, the crosslinking system comprising: a primary
crosslinking agent selected from the group consisting of an alkali
metal bicarbonate and a salt of a phosphoric acid, wherein the
primary crosslinking agent generates a first crosslink density in
the binder; a secondary crosslinking agent comprising an alkali
metal carbonate, wherein the secondary crosslinking agent generates
a second crosslink density in the binder, and a tertiary
crosslinking agent that generates a third crosslink density in the
binder, wherein the crosslinking system crosslinks the polymeric
binder forming the play composition, and wherein the first
crosslink density is greater than both the second crosslink density
and the third crosslink density.
19. The crosslinking system of claim 18, wherein: the primary
crosslinking agent is effective to crosslink the binder in a pH
range of 8.5-10; and the secondary crosslinking agent is effective
to crosslink the binder in a pH range of 5.1 to 8.4.
20. The crosslinking system of claim 18, wherein: the primary
crosslinking agent is selected from the group consisting of sodium
phosphate dibasic and potassium bicarbonate; the secondary
crosslinking agent is sodium carbonate; and the tertiary
crosslinking agent is sodium tetraborate.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/957,721, entitled "Play Composition
Including Crosslinkable Binder," filed Dec. 1, 2010, the disclosure
of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention is directed toward play compositions
formed of a binder and a cross-linking system including a water
soluble salt complex.
BACKGROUND OF THE INVENTION
[0003] Through the years, play compositions of different types have
been provided by practitioners in the toy arts to amuse children
and adults and to aid in the development of manual skills and
dexterity, as well as creativity. While the variety of such play
material compositions is numerous, all generally involve the use of
free-forming or malleable materials that are manipulated and shaped
by the user. Certain materials have been provided which are
moldable and tend to retain their shapes (e.g., modeling clay),
while others are looser and more free-flowing. Others still are
gels having fluid-like flow characteristics.
[0004] Regardless of the type of play compositions used, it is
essential that such materials be safe for young children. Safety
requirements generally mandate that play material compositions be
nonirritating to the skin and eyes, and be nontoxic if ingested.
Additional requirements have been expected of these materials to
avoid damage to clothing, upholstery fabric, or carpeting.
Conventional play compositions such as those described above
typically include boron compounds such as sodium tetraborate that
function as a crosslinking agent. Boron compounds, while an
effective crosslinking agent, have recently come under scrutiny by
some as a potential irritant when present in high concentrations.
Lowering the amount of boron compounds in a composition, however,
deteriorates the polymer network the compounds are intended to
create. Thus, it is desirable to formulate a crosslinking system
that minimizes the amount of boron compounds (and, in particular,
sodium tetraborate) while providing the crosslinking properties
necessary to form usable play compositions.
SUMMARY OF THE INVENTION
[0005] The present invention is directed toward water-based play
compositions including a crosslinkable network polymer and a
crosslinking system effective to crosslink the polymer. The
crosslinking system is a water-soluble salt complex including a
primary crosslinking agent, a secondary crosslinking agent, and a
tertiary crosslinking agent. The primary crosslinking agent is a
water-soluble alkali metal salt or a phosphoric acid sodium salt.
The secondary crosslinking agent is a water-soluble alkali metal
salt. The tertiary crosslinking agent is a water soluble-boric acid
salt. The crosslinking system contains a diminished amount of boron
compounds while remaining effective in crosslinking network
polymers including polyvinyl alcohol (to form moldable dough
compositions) and guar gum (to form hydrogels).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0006] The crosslinking system of the present invention generates
crosslinks between molecules of a crosslinkable polymer to form a
polymer network. The crosslinking system is a water-soluble salt
complex including a primary crosslinking agent, a secondary
crosslinking agent, and a tertiary crosslinking agent (also called
a gelling agent or chelating agent). The primary crosslinking agent
generates the largest crosslink density in the network polymer
(i.e., the binder of the play composition) compared to the other
agents within the crosslinking system. That is, the primary
crosslinking agent generates the largest number of crosslinks per
unit volume in the network polymer. In an embodiment of the present
invention, the primary crosslinking agent generates at least about
45% of the crosslinks within the network polymer. By way of
example, the primary crosslinking agent generates about 55% of the
crosslinks within the network polymer. The primary crosslinking
agent is effective in alkaline environments (e.g., environments
having pH ranges of 8.5-10). In an embodiment of the present
invention, the primary crosslinking agent is a water-soluble alkali
metal bicarbonate. By way of example, the primary crosslinking
agent is potassium bicarbonate (KHCO.sub.3). Alternative compounds
may include magnesium bicarbonate, sodium bicarbonate, derivatives
thereof and combinations thereof. In another embodiment of the
present invention, the primary crosslinking agent is a salt of a
phosphoric acid such as disodium hydrogen phosphate
(Na.sub.2HPO.sub.4, also known as sodium phosphate dibasic),
magnesium phosphate dibasic, potassium phosphate dibasic,
derivatives thereof, and combinations thereof.
[0007] Each of the secondary and tertiary crosslinking agents in
the crosslinking system of the present invention generates a lower
crosslinking density than that of the primary crosslinking agent
(i.e., each generates a lower number of crosslinks per unit volume
in the polymer network). In an embodiment, the secondary
crosslinking agent generates no more than about 30% of the
crosslinks within the network polymer. By way of example, the
secondary crosslinking agent generates about 25% of the crosslinks
in the network polymer. In an embodiment, the secondary
crosslinking agent is a water-soluble alkali metal carbonate. By
way of example, the secondary crosslinking agent is a sodium
carbonate (Na.sub.2CO.sub.3), sodium sulfate, potassium sulfate,
potassium carbonate, magnesium carbonate, derivatives thereof and
combinations thereof. The secondary crosslinking agent is selected
to be effective within a slightly acidic to slightly alkaline
environment (e.g., environments having pH ranges of 5.1-8.4)
[0008] The tertiary crosslinking agent may generate a lower
crosslink density than both the primary and secondary crosslinking
agents. The tertiary crosslinking agent may generate no more than
25% of the crosslinks within the network polymer. By way of example
the tertiary crosslinking agent generates about 15%-20% of the
crosslinks within the network polymer. In an embodiment of the
present invention, the tertiary crosslinking agent is a boron
compound such as salts of boric acid. By way of example, the
tertiary crosslinking agent is sodium tetraborate
(Na.sub.2B.sub.4O.sub.7). The tertiary crosslinking agent is
selected to be effective in acidic to alkaline environments (e.g.
environments having a pH of 5.1-9.5).
[0009] In an embodiment of the present invention, the primary
crosslinking agent is present in the largest amount within the
crosslinking system. The secondary crosslinking agent, in turn, is
present in an amount less than the primary crosslinking agent, but
greater than the amount of the tertiary crosslinking agent.
[0010] The agents of the crosslinking system are present in amounts
effective to generate the desired level of crosslinking of the
binder forming the play composition. For example, when the primary
crosslinking agent is sodium phosphate dibasic, the primary
crosslinking agent is added to the play composition in an amount of
about 0.10 wt % to about 1.5 wt %; the secondary crosslinking agent
is added to the play composition in an amount of from about 0.01 wt
% to about 0.50 wt %; and the tertiary crosslinking agent is added
to the play composition in an amount of from about 0.005 wt % to
about 0.50 wt % (based on the total weight of the play
composition). By way of further example, when the primary
crosslinking agent is potassium bicarbonate, the primary
crosslinking agent is added to the play composition in an amount of
about 0.50 wt % to about 3 wt %, the secondary crosslinking agent
is added to the play composition in an amount of from about 0.10 wt
% to about 0.80 wt %; and the tertiary crosslinking agent is added
to the play composition in an amount of from about 0.005 wt % to
about 0.50 wt % (based on the total weight of the play
composition).
[0011] The above formulation provides a crosslinking system
including a salt complex effective to crosslink the binder
throughout various pH levels. The system, while including a
substantially lower amount of boron compounds than conventional
compositions, is highly effective at creating the desired polymer
network. By way of example, the amount of borate compound utilized
to crosslink the play composition is less than about 0.50% by
weight play composition. Preferably, the amount of borate compound
utilized is less than about 0.10% by weight play composition.
[0012] As noted above, the crosslinking system in accordance with
the present invention is utilized to form play compositions having
desired properties. In an embodiment, the crosslinking system is
utilized to form gel compositions having cold flow characteristics.
For example, the crosslinking system may be utilized in the
formation of a flowable gel composition including a polymer or
colloidal network that is expanded throughout its whole volume by a
fluid. Specifically, the play composition is a hydrogel having
distinct flow properties--the gel is amorphous, possesses a high
flow rate, and can be recombined after tearing (i.e., the gel is
self-healing).
[0013] The gel composition includes water and a polymer binder
(i.e., a network polymer) crosslinked with the above-described
crosslinking system. While tap water may be utilized, deionized
water is preferred to minimize the occurrence of any impurities
that may interfere with crosslinking. In an embodiment of the
present invention, water is present within the gel composition in
an amount of about 75 wt % or more and, in particular, about 90 wt
% or more. By way of example, the water is present in an amount of
about 95% by weight gel composition. Water content below the lower
threshold leads to incomplete hydrolysis of the binder (resulting
in partial cross-linking), while water in excess of 95% results in
excess water, which weakens the polymer network.
[0014] In an embodiment, the polymer binder is a network forming
guar polymer such as guar gum (C.sub.21H.sub.36O.sub.15) and guar
derivatives. Guar derivatives include hydroxypropyl guar (HPG),
carboxymethyl guar (CMG), carboxymethyl hydroxypropyl guar (CMHPG),
and carboxymethyl cellulose. The guar polymers may be nonionic,
anionic, or cationic. In an embodiment of the present invention,
the polymer binder is present within the gel composition in an
amount of about 0.50 wt % to about 3 wt %. By way of example, the
amount of polymer binder present is about 1% by weight gel
composition.
[0015] The crosslinking system includes a combination of agents
present in an amount effective to achieve the gel point of the
polymer network. In an embodiment of the present invention, the
crosslinking system is present within the gel composition in an
amount of about 0.10 wt % to about 2.5 wt % and, in particular,
about 0.05 wt % to about 2 wt %. By way of example, the amount of
crosslinking system present is about 0.65% by weight within the gel
composition. In an embodiment of the present invention, the primary
crosslinking agent is disodium hydrogen phosphate, the secondary
crosslinking agent is sodium carbonate, and the tertiary
crosslinking agent is sodium tetraborate. In an embodiment of the
present invention, the primary crosslinking agent is present within
the gel composition in an amount of about 0.10 wt % to about 1.50
wt %, the secondary crosslinking agent is present in an amount of
about 0.01 wt % to about 0.50 wt %, and the tertiary crosslinking
agent is present in an amount of about 0.005 wt % to about 0.5 wt
%. By way of example, the amount of primary crosslinking is about
0.40% by weight gel composition, the amount of secondary
crosslinking agent is about 0.15% by weight gel composition, and
the amount of tertiary crosslinking agent is about 0.05% by weight
gel composition. In an embodiment of the present invention, the
amount of borate compound present in the gel composition is less
than about 0.50 wt %, and preferably less than about 0.10 wt %.
[0016] The gel composition may include one or more additives. By
way of example, the gel composition includes a preservative in an
amount of from about 0.50 wt % to about 1.50 wt %. The preservative
may include, but is not limited to, phenoxyethanol, methylparaben,
ethylparaben, butlyparaben, propylparaben, isobutylparaben and
combinations of two or more of the above. By way of specific
example, the composition may include about 1 wt % Phenonip.RTM. XB
(a preservative blend available from Clariant International AG,
Muttenz, Switzerland). Many other commercially available
preservatives well known to those skilled in the art may also be
utilized.
[0017] The gel composition of the present invention may also
include one or more humectants. Humectants are hygroscopic
substances that capture water via absorption or adsorption. Thus,
humectants not only aid in the prevention of water loss from the
composition, but will capture additional water from the
environment. In an embodiment of the present invention, the
humectant is present within the gel composition in an amount of
about 1 wt % to about 3 wt %. By way of example, the amount of
humectant is about 2% by weight gel composition. In an embodiment
of the present invention, the humectant is glycerin, diols such as
polyethylene glycol, propylene glycol, ethylene glycol, derivatives
thereof and mixtures thereof. Humectants such as glycerin and
polyethylene glycol also function as plasticizers (promoting
elongation/stretch of the composition) and/or dispersants (improve
the separation of particles and to prevent settling or
clumping).
[0018] The gel composition of the present invention may further
include a colorant (e.g., a pigment or dye) to enhance its
entertainment or play effect. Typical colorants include FD&C
Powder Series colorants (available from Sensient Technologies
Corporation, Milwaukee, Wis.), as well as the DayGlo.RTM. T-Series
colorants (available from DayGlo Color Corporation, Cleveland,
Ohio). The colorant may be present within the gel composition in an
amount of about 0.50 wt % to about 2.50 wt %. By way of example,
the amount of colorant present is about 1% by weight gel
composition.
[0019] The above described gel composition possesses several unique
properties, including a specific gravity of approximately 0.8-1.4,
a density of approximately 0.8-1.4 g/cm.sup.3; and a viscosity of
less than about 1000 cP (e.g., about 500 cP to about 1000 cP). The
gel composition, moreover, possesses a pH value of 7 or above. By
way of example, the gel composition may possess a pH value of about
8.3.
[0020] In an embodiment of the present invention, the process to
form the gel composition includes the formation and subsequent
combining of separate binder and crosslinking system formulations.
In a first mixing vessel (e.g., a mixing vessel fitted with a sweep
and a homogenizer) a binder formulation or phase is created. A
predetermined amount of water at room temperature (e.g., deionized
water constituting about 90 wt % of the final composition) is added
to the first vessel, along with additives (e.g., preservatives or
humectants), and stirring occurs for a predetermined period of time
(e.g., about 5-15 minutes). Colorant may be added, followed by the
addition of the binder. The resulting solution is mixed for a
predetermined period of time to incorporate the binder (e.g., about
3-10 minutes). The solution is then heated to a predetermined
temperature range (e.g., 90.degree. F. to 130.degree. F.), and the
heated solution is mixed for a predetermined amount of time (e.g.,
3-10 minutes).
[0021] In a second mixing vessel, the crosslinking system
formulation or phase is formed. The primary crosslinking agent, the
secondary crosslinking agent, and the tertiary crosslinking agent
are added to the second mixing vessel. The remaining water is added
and the resulting solution is heated to a predetermined temperature
range (e.g., 130.degree. F. to 190.degree. F.). Alternatively, the
water may be heated to the predetermined temperature range before
its addition to the second mixing vessel. The solution is then
maintained at the predetermined temperature to permit dissolution
of the crosslinking system components into the water. Once the
components of the crosslinking system have dissolved, the
crosslinking formulation is added to the first mixing vessel
containing the binder formulation. The combined formulations are
mixed, forming the gel composition.
[0022] A formulation for a gel composition in accordance with an
embodiment of the present invention is provided in the example
below with reference made to Table I.
EXAMPLE
TABLE-US-00001 [0023] TABLE I Ingredient Approximate Weight %
Deionized Water 94 Binder 1 Crosslinking System Sodium Phosphate
(dibasic) 0.40 Sodium Carbonate (anhydrous) 0.15 Sodium Tetraborate
(anhydrous) 0.05 Additives (humectant, preservative, 4
colorant)
[0024] About 90 wt % water, humectant (glycerin 99.5%), and
preservative (Phenonip.RTM. XB, available from Clariant
International Ltd) were added to a mixing vessel and mixed for
about 10 minutes. The colorant (FD&C Powder Series, Sensient
Technologies.RTM., Milwaukee, Wis.) was added, along with the
binder (carboxymethyl hydroxypropyl guar (CMHPG), available from
Economy Polymers & Chemicals, Houston, Tex.). The resulting
solution was mixed for about five minutes, and then heated to a
temperature of about 115.degree. F. Once heated, the temperature
was maintained and the mixing continued for an additional about
five minutes. In a second mixing vessel, the sodium phosphate
(Spectrum.RTM. Chemicals & Laboratory Products), sodium
carbonate (Spectrum.RTM. Chemicals & Laboratory Products),
sodium tetraborate (Spectrum.RTM. Chemicals & Laboratory
Products), and the remaining water was combined, with the resulting
mixture being heated to a temperature of about 170.degree. F. to
form a crosslinking solution. The crosslinking solution as added to
the solution containing CMHPG, and the resulting mixture was
stirred until a viscous gel composition was formed.
[0025] The resulting gel composition possessed a measured specific
gravity (measured with a GARDCO device) of approximately 1.1 (at
24.degree. C.); a measured density (at 24.degree. C.) of
approximately 1.1 g/cm.sup.3; a measured pH (at 24.degree. C.) of
approximately 8.34; and a measured viscosity (measure at 49.degree.
C. with a Brookfield Model FV-II Viscometer) of approximately 720
cP.
[0026] The above described formulation provides a playable,
cohesive, nontoxic gel composition which has a stretchable, slimy
consistency and tactile feel characteristic. The gel has a healable
property so that if pulled apart, upon manipulation it will
re-adhere to itself. It is believed that the crosslinking system of
the present invention generates bonds that, while strong, are
dynamic, such that they are constantly forming and dissociating,
with the crosslinks moving randomly among the binder molecules. The
result is that over short intervals, the strength of the crosslinks
gives the gel composition its resilience, but over longer periods,
the dynamic nature of the crosslinks allows the binder molecules to
move relative to each other to provide the composition with its
consistency.
[0027] One property of the gel composition of the present invention
is a rheology which allows the composition to be formed into molded
shapes, as well as to be integrally free flowing between fingers or
down inclines. Another property of the gel is its cohesive nature
which allows it to be stretched into long strands or stretched into
thin membranes without breaking. A still further property of the
instant play gel is its unexpected ability to conduct electricity,
indicating an ionic mobility characteristic of the gel. The
resulting integral mass behaves much like a free flowing amorphous
"blob" which easily tears, packs, and recombines and will blanket
or coat any surface to which is applied. The play gel material is
malleable, pliable, free flowing; has a satisfactory tactile feel;
can be used for long periods of time without drying to the point
that it becomes unusable; would not be harmful if accidentally
ingested; and exhibits a bright, shiny colorful appearance with no
unpleasant odor. The play material can be simply cleaned-up and
removed from carpets and fabrics with water.
[0028] The crosslinking system of the present invention may further
be utilized in forming a moldable play composition or dough having
soil-like characteristics. In an embodiment of the present
invention, the dough composition includes particulate filler, a
polymer binder, a thickener, a solvent, and the crosslinking
system. The particulate filler may possess any suitable size and
shape. In an embodiment of the present invention, the particulate
filler possesses a particle size of less than about 100 .mu.m and,
in particular, of about 8 .mu.m to 60 .mu.m. The particulate filler
includes, but is not limited to silica, granular material such as
sand, and polymer microspheres such as Expancel.RTM. DE
microspheres (available from AzkoNobel.RTM., Sweden). In an
embodiment, the particulate filler constitutes the largest
component of the dough composition (measured by weight percent). In
one embodiment of the present invention (e.g., when sand is
utilized as the filler), the particulate filler may be present
within the dough composition in an amount of about 30 wt % to about
50 wt % (e.g., about 40% by weight dough composition). In another
embodiment (e.g., when polymer microspheres are utilized as the
filler), the particulate filler may be present within the dough
composition in an amount of about 3 wt % to about 45 wt %.
[0029] The binder includes crosslinkable polymers including vinyl
acetate resins such as polyvinyl alcohol, polyacrylic acid, and
combinations thereof. In an embodiment of the present invention,
the polymeric binder may be fully or partially hydrolyzed polyvinyl
alcohol. By way of example, the polyvinyl alcohol is a partially
hydrolyzed polyvinyl alcohol having a degree of hydrolysis of 80 to
95 mol % (e.g., CELVOL 205 (88% hydrolyzed), available from Sekisu
Specialty Chemicals, Dallas, Tex.). The polymeric binder may be
present within the dough composition in an amount of about 4 wt %
to about 15 wt % and, in particular, in an amount of about 5.50 wt
% to about 11.50 wt %. By way of example, the amount of polymeric
binder is about 8.50% by weight dough composition. In an embodiment
of the present invention, the binder material is polyvinyl
pyrrolidine, polyvinyl acetate, and mixtures thereof.
[0030] The thickener increases the viscosity of the dough
composition, providing body, increasing stability, and improving
suspension of ingredients. In an embodiment of the present
invention, the thickener includes water-soluble polymers such as
polysaccharides. By way of example, the thickener includes methyl
cellulose, hydroxymethylcellulose, hydroxyethylcellulose, guar gum,
and modified versions of the aforementioned such as guar gum
derivatives (e.g., carboxymethyl hydroxypropyl guar). The thickener
may be present within the dough composition in an amount of about
0.30 wt % to about 1.50 wt %. By way of example, the amount of
thickener is about 0.70% by weight dough composition.
[0031] The crosslinking system of the present invention includes a
combination of agents present in an amount effective to achieve
formation of the polymer network. In an embodiment of the present
invention, the crosslinking system is present in the dough
composition in an amount of about 0.45 wt % to about 4.0 wt %. By
way of example, the amount of crosslinking system is about 1.0% by
weight dough composition. In an embodiment of the present
invention, the primary crosslinking agent is present in an amount
of about 0.50 wt % to about 3 wt %, the secondary crosslinking
agent present in an amount of about 0.10 wt % to about 0.80 wt %,
and the tertiary crosslinking agent is present in an amount of
about 0.005 wt % to about 0.50 wt %. By way of specific example,
the primary crosslinking agent is present in an amount of about 1%
by weight dough composition, the secondary crosslinking agent
present in an amount of about 0.15% by weight dough composition,
and the tertiary crosslinking agent is present in an amount of
about 0.09% by weight dough composition.
[0032] In an embodiment of the present invention, the primary
crosslinking agent is potassium bicarbonate, the secondary
crosslinking agent is sodium carbonate, and the tertiary
crosslinking agent is sodium tetraborate. The amount of borate
compound utilized in the dough composition is preferably less than
about 0.50% by weight, and more preferably less than about 0.10% by
weight.
[0033] In an embodiment of the present invention, the dough
composition further includes a plasticizer to increase the
plasticity of the composition. By way of example, the plasticizer
includes diols such as ethylene glycol, propylene glycol,
polyethylene glycol, polypropylene glycol, and combinations
thereof. By way of specific example, the plasticizer is propylene
glycol. The plasticizer may be present within the dough composition
in an amount of about 2 wt % to about 10 wt % and, in particular,
in an amount of about 3 wt % to about 7 wt %. By way of example,
the amount of plasticizer is about 5% by weight dough
composition.
[0034] In an embodiment of the present invention, the dough
composition further includes a humectant to inhibit drying of the
composition (by absorbing/adsorbing water). By way of example, the
humectant is a polyol such as glycerin. The glycerin may present
within the dough composition in an amount of about 0.50 wt % to
about 8 wt % and, in particular, about 1 wt % to about 5 wt %. By
way of example, the amount of humectant is about 3% by weight dough
composition.
[0035] Water is generally used as the solvent. Tap water may be
utilized; however, deionized water is preferred to minimize the
potential for impurities that could interfere with crosslinking. In
an embodiment of the present invention, water is present within the
dough composition in an amount of about 25 wt % to about 75 wt %.
By way of example, the amount of water present is about 35% by
weight dough composition.
[0036] In an embodiment of the present invention, the dough
composition includes various additives. For example, the
composition may include an opacifying agent such as an acrylate
emulsion (e.g., a styrene/acrylic emulsion (Acusol.RTM. OP301,
available from Dow.RTM.)). The opacifying agent may be present
within the dough composition in an amount of about 1 wt % to about
4 wt % (e.g., about 2 wt %). In addition, the dough composition of
the present invention may include an antifoaming agent such as a
silicone emulsion (e.g., Antifoam FG-10, available from Dow
Corning.RTM.) present in an amount of about 0.10 wt % to about 1 wt
% (e.g., 0.30 wt %).
[0037] Releasing agents can also be added to the dough composition
of the present invention to reduce tackiness. Typical releasing
agents include mineral oil, petroleum, and silicon wax (e.g.,
Xiameter.RTM. 200 polydimethylsiloxane, available from Dow
Corning.RTM.) present in the composition in an amount of about 0.50
wt % to about 3 wt % (e.g., about 2 wt %). A preservative can be
added to the dough composition of the present invention to increase
shelf life, and a wide variety of preservatives are available. By
way of example, preservatives include, but are not limited to,
phenoxyethanol, methylparaben, ethylparaben, butlyparaben,
propylparaben, isobutylparaben and combinations of two or more of
the above. By way of specific example, the composition may include
about 1 wt % Phenonip.RTM. XB (a preservative blend available from
Clariant International AG, Muttenz, Switzerland). Many other
commercially available preservatives well known to those skilled in
the art may be used. In an embodiment of the present invention, the
preservative is present within the dough composition in an amount
of about 0.50 wt % to about 1.50 wt %.
[0038] The dough composition of the present invention may further
include a colorant (e.g., a pigment or dye) to enhance its
entertainment or play effect. Typical colorants include FD&C
Powder Series or Iron Oxide Series colorants (available from
Sensient Technologies Corporation, Milwaukee, Wis.), as well as the
DayGlo.RTM. T-Series colorants (available from DayGlo Color
Corporation, Cleveland, Ohio). The colorant may be present in an
amount of about 0.50 wt % to about 2.50 wt %. By way of example,
the amount of colorant is about 1% by weight dough composition. The
dough composition of the present invention may further include a
softening oil such as petroleum oil (e.g., a white mineral oil such
as Drakeol.RTM. 9, available from Calumet Specialty Products
Partners) present in an amount of about 1 wt % to about 3 wt %
(e.g., about 2 wt %).
[0039] A formulation for a moldable dough composition in accordance
with an embodiment of the present invention is provided in the
example below with reference made to Table II.
EXAMPLE
TABLE-US-00002 [0040] TABLE II Ingredient Approximate Weight %
Deionized Water 34 Particulate Filler 40 Binder 8 Plasticizer 5
Humectant 3 Opacifying Agent 2 Mineral Oil 2 Crosslinking System
Potassium Bicarbonate 1 Sodium Carbonate (anhydrous) 0.15 Sodium
Tetraborate (anhydrous) 0.10 Misc (preservatives, colorant, 5
antifoaming agent, release agent, thickener)
[0041] Initially, a binder formulation is created. About 25 wt %
deionized water at room temperature was added to a first vessel in
the form of a jacketed mixing tank fitted with a mixer, a sweep, a
turbine, and a homogenizer. The binder (Celvol.RTM. 205 Polyvinyl
Alcohol, 88% hydrolyzed, available from Sekisui Specialty
Chemicals, LLC, Dallas, Tex.) is added and mixed for about 10
minutes. The resulting solution is heated to a temperature of about
88.degree. C.-93.degree. C. The homogenizer is deactivated, and
mixing continues for about 2-3 hours at the elevated
temperature.
[0042] The now homogenous solution is cooled to room temperature.
The plasticizer (propylene glycol, Spectrum.RTM. Chemicals &
Laboratory Products), the humectant (glycerin 99.5%, Spectrum.RTM.
Chemicals & Laboratory Products), and the thickener
(hydroxyethylcellulose, Natrosol.RTM. 250 HH CS, Ashland Chemical
Aqualon Division, Wilmington, Del.) are added, and mixing is
continued for about 15 minutes. The colorant (Iron Oxide Series
pigment, Sensient Technologies.RTM., Milwaukee, Wis.) is added, and
mixing is continued about 5 minutes. The preservative
(Phenonip.RTM. XB, available from Clariant International Ltd) is
then added and mixing continued for about 20 minutes.
[0043] In a second mixing vessel, a crosslinking system formulation
is created. Specifically, the potassium bicarbonate (Spectrum.RTM.
Chemicals & Laboratory Products), sodium carbonate
(Spectrum.RTM. Chemicals & Laboratory Products), sodium
tetraborate (Spectrum.RTM. Chemicals & Laboratory Products),
and the remaining water is combined, and then mixed until
dissolved.
[0044] In a third mixing vessel (e.g., a Hobart mixing bowl), the
particulate filler (silica sand, available from Sand Art), the
mineral oil (Drakeol.RTM. 9, available from Calumet Specialty
Products partners, LP), and any other fillers are combined. The
binder solution from the first mixing vessel is added and mixed
until dispersed (about 15 minutes). Finally, the crosslinking
solution from the second mixing vessel is added, and the combined
mixtures are mixed until the desired material is formed.
[0045] The resulting composition is a modeling dough material that
is kneadable, moldable, pliant and ductile enough to avoid tearing
during use; that can be used for long periods of time without
drying to the point that it becomes unusable; that is not harmful
if accidentally ingested; and that exhibits a pleasant tactile feel
with no unpleasant odor. The dough composition of the present
invention possesses a unique combination of properties, including
both a high degree of stretchability and a high degree of
pliability when stress is applied. It does not flow appreciably
under a rapid blow, but will flow readily under the application of
a low, steady pressure. Other properties include excellent
stability throughout a very wide temperature range.
[0046] While the present inventions have been described in detail
and with reference to specific embodiments thereof, it will be
apparent to one skilled in the art that various changes and
modifications can be made therein without departing from the spirit
and scope thereof. Weight percent refers to the amount of a
component within the finished composition, unless otherwise noted.
While the process for forming the compositions includes preferred
steps, as well as preferred time and temperature parameters, it
should be understood that the play compositions may be formulation
utilizing other process steps, other temperatures, and other mixing
times. Thus, it is intended that the present invention covers the
modifications and variations of these inventions provided they come
within the scope of the appended claims and their equivalents.
Terms such as "first," "second," "third," etc., merely identify one
of a number of portions, components and/or points of reference as
disclosed herein, and do not limit the present inventions to any
particular compositions, configurations, or orientations. Although
the disclosed inventions are illustrated and described herein as
embodied in one or more specific examples, it is nevertheless not
intended to be limited to the details shown, since various
modifications and structural changes may be made therein without
departing from the scope of the inventions. In addition, various
features from one of the embodiments may be incorporated into
another of the embodiments. Accordingly, it is appropriate that the
inventions be construed broadly and in a manner consistent with the
scope of the disclosure.
[0047] Having described preferred embodiments, it is believed that
other modifications, variations and changes will be suggested to
those skilled in the art in view of the teachings set forth herein.
It is therefore to be understood that all such variations,
modifications and changes are believed to fall within the scope of
the present invention as defined by the appended claims. Although
specific terms are employed herein, they are used in a generic and
descriptive sense only and not for purposes of limitation.
* * * * *