Flowable, pressure-compensating material compositions are provided. The compositions are directed toward improving one or more aspects of the flowable material, such as by providing/improving flame retardancy and/or the homogeneity of the composition over time. For instance, one composition includes a liquid, a viscosity-increasing material, and beads having a preselected coating thereon to provide for a coupling interaction with at least one of the liquid and the viscosity-increasing material.

FIELD OF THE INVENTION 
This invention relates generally to the field of flowable materials and, 
more particularly, to flowable, pressure-compensating materials for human 
anatomy padding applications. 
BACKGROUND OF THE INVENTION 
Various padding devices have been employed in the past. Examples include 
liquid- or gas-filled bladders, e.g., water-filled cushions and pneumatic 
pads; and gases or liquids dispersed in a solid material, e.g., foams and 
gels. Generally, such padding devices operate on the principle of 
conformation to the shape of an object when placed under pressure. When a 
force, such as a person's mass, is placed on such a padding device, the 
device deforms so as to conform to the shape of the pressure-applying 
object in order to distribute the force over as large an area as possible. 
These devices perform adequately when the object being padded has a 
relatively large, uniformly shaped surface area. However, when the object 
being padded includes a relatively small area of concentrated force, such 
as that caused by a bony protuberance, the majority of known padding 
devices do not perform to adequately reduce the discomfort of users in 
many applications. This is because such padding devices exert greater 
responsive pressure on the area of concentrated force. 
The reason for the greater pressure is that materials employed in prior art 
padding devices typically have a high degree of "memory." As used herein, 
the term "memory" will refer to that characteristic of a material in which 
the material returns to its original shape as a result of internal 
restoring forces when an external force is removed. Such materials deform 
to the shape of an object which applies an external force by compressing. 
However, due to the internal restoring forces, a pressure which is 
proportional to the degree of compression is exerted against the object 
which applies the external force. A sharp protuberance compresses the 
padding device more than the surrounding areas and, as a result, the 
padding device presses back with greater pressure in these areas of high 
compression. Such areas of high pressure are especially undesirable when 
the protuberance is a bone, such as an ankle or ischial tuberosity. The 
high pressure can lead to discomfort and, after periods of extended use, 
to actual damage to the tissue overlying the protruding bone. 
The problem can be described with reference to a padding device comprising 
a gas dispersed in a solid material, e.g., foam. Tiny gas bubbles in foam 
act like millions of coil "springs." When an irregularly shaped object, 
such as a human body portion, exerts a force on the foam padding device, 
the "springs" are compressed to varying degrees, each pushing back on the 
body portion with a force proportional to the amount of compression. This 
produces differential pressures across the body portion coinciding with 
the padding device which in and of itself causes a certain degree of 
discomfort. In order to achieve intimate conformity with the human body 
portion, a relatively soft foam may be utilized, which can be compared to 
weak "springs." However, when bony protuberances exert a concentrated 
force on these soft foams the "springs" are greatly compressed and thus, 
exert larger forces against the coinciding body portion, thereby possibly 
causing pain and reduced circulation. Moreover, if the foam is too soft 
there may be total compression and thus a bottoming out effect such that 
the foam actually provides little or no padding in these areas. The 
problem exists and is even more pronounced if a stiffer foam is employed, 
because the "springs" are stronger and thus the forces applied back 
against the human body portion will be greater, particularly in areas 
coinciding with bony protuberance. Intimate conformity is also more 
difficult to achieve with stiffer foams. 
Deformable silicone gel padding devices are disclosed in U.S. Pat. No. 
3,449,844 by Spence, issued Jun. 17, 1969; U.S. Pat. No. 4,380,569 by 
Shaw, issued Apr. 19, 1983; U.S. Pat. No. 3,663,973 by Spence, issued May 
23, 1972; U.S. Pat. No. 3,548,420 by Spence, issued Dec. 22, 1970; U.S. 
Pat. No. 3,308,491 by Spence, issued Mar. 14, 1967; U.S. Pat. No. 
4,019,209 by Spence issued Apr. 26, 1977; and U.S. Pat. No. 4,668,564 by 
Orchard, issued May 26, 1987. In U.S. Pat. No. 4,380,569, a silicone gel 
containing glass microbeads is disclosed. 
The silicone gel disclosed in these patents, being a cross-linked and 
extended chain polymer, is described as having near total memory. In other 
words, it returns to its original shape when an external force is removed. 
The internal restoring forces necessary to provide such memory are 
undesirable in some applications. In use, differential pressures will 
result depending upon the degree of deformation of the silicone gel 
material, with higher deformation resulting in localized areas of high 
pressure being exerted on the external pressure-applying object. 
In order to alleviate the problem of differential pressure inherent with 
many prior art materials, flowable, pressure-compensating materials were 
developed. Such materials and applications thereof are described in U.S. 
Pat. No. 3,402,411 by Alden Hanson, issued Sep. 24, 1968; U.S. Pat. No. 
3,635,849 by Alden Hanson, issued Jan. 18, 1972; U.S. Pat. No. 4,038,762 
by Swan, Jr., issued Aug. 2, 1977; U.S. Pat. No. 4,083,127 by Chris 
Hanson, issued Apr. 11, 1978; U.S. Pat. No. 4,108,928 by Swan, Jr., issued 
Aug. 22, 1978; U.S. Pat. No. 4,144,658 by Swan, Jr., issued Mar. 20, 1979; 
U.S. Pat. No. 4,229,546 by Swan, Jr., issued Oct. 21, 1980; and U.S. Pat. 
No. 4,243,754 by Swan, Jr., issued Jan. 6, 1981. Each of these U.S. 
patents is incorporated herein by reference in its entirety. These patents 
will collectively be referred to as the "flowable, pressure-compensating 
material patents." 
The preferred materials disclosed in U.S. Pat. No. 3,402,411 comprise from 
20 to 25 weight percent polyisobutylene, from 25 to 37.5 weight percent of 
an inert oil, e.g. mineral oil or a saturated ester oil or a mixture 
thereof, and from 42.5 to 50 weight percent inorganic filler. U.S. Pat. 
No. 3,635,849 discloses a composition consisting essentially of from about 
5 to about 45 weight percent of a polyolefin, particularly 
polyisobutylene, from about 15 to about 70 weight percent of a paraffin, 
and from about 5 to about 80 weight percent oil. Lightweight aggregate 
materials, for example, polystyrene beads or a heavy aggregate such as 
Fe.sub.3 O.sub.4 can also be added. 
The flowable, pressure-compensating materials disclosed in U.S. Patent Nos. 
4,038,762, 4,108,928 and 4,243,754 include from 21.39 to 77.96 weight 
percent oil, 21.04 to 69.62 weight percent wax and 1 to 9 weight percent 
microbeads. U.S. Patent Nos. 4,144,658 and 4,229,546 disclose flowable, 
pressure-compensating materials comprising 10 to 60 weight percent hollow, 
glass microbeads, 8.5 to 34 weight percent wax and 26.5 to 81 weight 
percent oil. U.S. Pat. No. 4,083,127 discloses a flowable, 
pressure-compensating fitting material consisting essentially of discrete, 
lightweight, sturdy microbeads distributed throughout a continuous phase 
of wax and oil. 
In use, the flowable, pressure-compensating materials disclosed in the 
above-mentioned patents are typically placed in a pliable package or 
envelope to define a padding device, such as by injecting the flowable 
material between two leak-proof resinous sheets which are sealed at the 
edges. The flowable materials act hydraulically. For instance, in 
applications where the force being transferred to the padding device is 
substantially constant (e.g., a seat cushion), flowable material in the 
region of the padding device coinciding with the applied force attempts to 
flow to other regions within the padding device away from the applied 
force (e.g., the flowable material is redistributed throughout the padding 
device to effectively equalize the pressure therewithin). Preferably, 
there is not a total evacuation of flowable material from the region 
coinciding with the applied force so that the user does not "bottom out" 
on the padding device and thereby experience a high force concentration 
and related discomfort. As a result of this migration of flowable material 
throughout the padding device, the applied force is distributed over a 
larger area, thereby reducing the pressure experienced by the user and 
relatedly enhancing user comfort (e.g., differential pressures throughout 
the padding device may be minimized by the transfer of flowable material 
throughout at least portions of the padding device). As can be 
appreciated, the larger the area over which the force can be distributed 
by having the padding device substantially conform to the user, through 
the described migration of flowable material and/or based upon a 
preconfigured/ precontoured padding device, pressures experienced by the 
user on the padding device can be minimized. 
Depending upon the particular padding application, the viscosity of the 
flowable materials can be varied to provide certain desired performance 
characteristics. For instance, in applications where the force applied to 
the padding device is more repetitive or cyclic in nature, such as in the 
self-reinitializing padding device disclosed in U.S. Pat. No. 5,131,174 by 
Drew et al., issued Jul. 21, 1992, lower viscosity flowable materials may 
be preferable. However, in the those padding applications in which the 
force is somewhat constant as described above and/or in applications where 
stability is an issue (e.g., where it is desirable to have the flowable 
material migrate/flow only when exposed to continually applied, versus 
instantaneously applied forces) higher viscosity materials may be used. 
However, increasing the viscosity of the flowable material does not 
decrease the ability of the flowable materials to conform to the shape of 
the force-applying object, only the rate at which they will migrate within 
the padding device, such as to achieve substantial conformance with the 
user to maximize force distribution. Consequently, by using high viscosity 
flowable materials the "reaction" or "response time" of the flowable 
material may be reduced, which again may be desirable for certain 
applications. Flowable materials are presently marketed under the 
trademark FLOLITE.TM. by Alden Laboratories, Inc. of Boulder, Colo. U.S.A. 
In many if not all padding applications which utilize flowable materials of 
the above-described type, it is generally desirable to retain a certain 
distribution of the various constituents throughout the flowable material 
(e.g., a homogeneous mixture). One particular constituent which may have a 
tendency to separate from remaining portions of the flowable material 
composition are beads, such as when the beads are substantially hollow to, 
inter alia, reduce the weight of the flowable material composition and 
thus the weight of the padding device. In order to redistribute the beads 
in the flowable material composition, the padding device may be kneaded. 
Notwithstanding the commercial success of existing flowable material 
compositions in padding applications, such as in wheelchair seat cushions, 
it can be appreciated that further reduction of kneading 
requirements/periodicity will further enhance the potential for commercial 
success of these types of padding devices. 
Flammability of the flowable material composition may also affect the 
extent of its commercial success in extending the use of flowable 
materials to additional padding applications. For instance, in the event 
that flowable material compositions are used in airplane and/or motor 
vehicle seat cushions, the potential exists that the padding device will 
be exposed to a relatively high heat source in the case of an accident. 
Moreover, there may be applications where there is an elevated temperature 
during normal use of the padding device. In order to make flowable 
materials commercially viable for these types of applications, it would be 
desirable for the flowable material and/or the envelope containing such 
flowable material to have a certain degree of flame retardancy. 
SUMMARY OF THE INVENTION 
The present invention generally relates to improvements of flowable, 
pressure-compensating materials used in fluid-tight enclosures for human 
anatomy padding applications. More particularly, the compositions of 
flowable materials in accordance with the present invention exhibit 
further reductions in the degree of separation of individual constituents 
over time and/or exhibit desired flame retardancy characteristics. 
One composition of a flowable material in accordance with the present 
invention includes a liquid, a viscosity-increasing material, and 
plurality of beads (e.g., substantially small, hollow or solid particles 
for influencing the flow characteristics of the composition, for enhancing 
load distribution, and/or for reducing the weight of the composition) 
having a preselected coating on an exterior surface thereof and a density 
which is different (e.g., less) than that of both the liquid and 
viscosity-increasing material. Based upon the relative densities of these 
constituents, the potential exists that the beads may float/settle out of 
the composition which may undesirably affect the 
characteristics/performance of the flowable material. As used herein, the 
terms "float/ floating out" "settle/settling out" mean a condition in 
which a particular constituent is not distributed throughout the flowable 
material to an acceptable degree, such as when beads migrate/collect at or 
near the "surface" of the flowable material. Therefore, in order to retain 
the beads within the composition for an acceptable period of time, the 
coating on the beads is selected to provide for an interaction/coupling 
effect with at least one of the liquid or the viscosity-increasing 
material. 
Appropriate viscosity-increasing materials for the above-described flowable 
material composition includes various clays (e.g., attapulgites and/or 
bentonites), fumed silica, and mixtures thereof; appropriate liquids 
include oil (e.g., mineral oils such as petroleum-derived oils and 
including where such liquid is all oil or combinations of oil and other 
materials such as wax), glycerin-containing solutions (e.g., all glycerin 
solutions or solutions containing a combination of glycerin and water), 
and polyhydroxyl alcohol solutions; and appropriate beads include those 
which are formed from resinous materials (e.g., acrylonitrile or 
polyvinylidene dichloride beads which each have a calcium carbonate 
coating thereon). Various combinations of these particular constituents 
have yielded desired results. 
One such combination of the above-identified constituents includes a 
glycerin-containing solution, attapulgite, and resinous beads having a 
calcium carbonate coating thereon. Another combination includes oil (e.g., 
mineral oils such as petroleum-derived oils), fumed silica or 
surface-treated bentonite, and resinous beads having the calcium carbonate 
coating thereon. In the case where beads having the calcium carbonate 
coating thereon are used with certain mineral viscosity-increasing 
materials and/or with certain liquids, it is believed that the small 
amount of water on the surface of the beads hydrogen bonds to the mineral 
viscosity-increasing material (e.g., bentonite surface treated with 
quartenary ammonium salts) and/or the liquid to retard or substantially 
prevent the beads from floating out of the composition over a given period 
of time. 
In certain combinations of liquids, viscosity-increasing materials, and 
beads in accordance with the flowable material compositions of the present 
invention, it may be desirable to incorporate one or more surfactants for 
purposes such as increasing the viscosity of the flowable material to a 
desired degree. For example, appropriate surfactants allow for increased 
viscosities to be achieved when using attapulgite and/or bentonite clays 
and/or fumed silica with oil (e.g., petroleum-derived oils), 
glycerin-containing solutions, and/or polyhydroxyl alcohol solutions. In 
these cases, the benefits achieved by using the above-described beads 
having the preselected coating thereon may be extended to flowable 
material compositions incorporating surfactants as well. 
In certain applications in accordance with flowable material compositions 
of the present invention, it may also be desirable to provide/improve 
flame retardancy. For instance, various flame retardants may be 
incorporated into the flowable material composition itself. Moreover, when 
the flowable material is contained within an envelope for a human anatomy 
padding application, the flame retardant may be selected to 
synergistically react with a halogen-containing material forming/defining 
at least a part of the envelope. Furthermore, a flame retardant cover may 
be positioned over the flowable material-containing envelope. In any case, 
flame retardancy is not necessarily dependent upon the type of beads, if 
any, selected/utilized in the flowable material composition. That is, the 
flowable material composition which is flame retarded to a certain degree 
does not necessarily have to include beads. However, certain types of 
beads may contribute to flame retardancy, such when using halogenous beads 
(e.g., polyvinylidene-dichloride beads) in combination with synergists 
such as antimony trioxide. 
As noted above, the flowable material compositions are used in human 
anatomy padding applications. In this case, the improved flowable material 
compositions of the present invention are contained within a fluid-tight, 
substantially pliable envelope/enclosure. In order to reduce the potential 
for the user bottoming out during use of the padding device (i.e., 
achieving surface-on-surface contact between opposing portions of the 
envelope/enclosure such that there is no flowable material coinciding with 
the application of the force to a portion of the human anatomy), the 
dimensions of the envelope/enclosure and/or the amount of flowable 
material within the envelope/ enclosure may be appropriately selected. 
One composition of an improved flowable material of the present invention 
suited for the above-described enclosure includes a liquid selected from 
the group consisting essentially of an oil-containing solution, a 
glycerin-containing solution, a polyhydroxyl alcohol-containing solution 
and appropriate mixtures thereof, as well as a viscosity-increasing 
material selected from the group consisting essentially of attapulgite, 
fumed silica, bentonite, and mixtures thereof. In addition, a coupling 
agent is also incorporated within the flowable material composition and is 
selected from the group consisting essentially of a surfactant, a 
plurality beads having the predetermined coating thereon such as the type 
noted above, or a combination thereof. Therefore, the above-identified 
combinations of constituents for flowable materials may each be 
incorporated into an enclosure for this human anatomy padding application.

DETAILED DESCRIPTION 
The present invention generally relates to improved compositions of 
flowable, pressure-compensating materials used in human anatomy padding 
applications. Compositions of these materials typically include a base 
liquid, some type of viscosity-increasing material, and beads. A variety 
of combinations of constituents for such flowable materials are disclosed 
herein which enhance one or more aspects of the flowable material. More 
particularly, the various improved compositions of flowable material 
exhibit further reduction in the degree of separation of individual 
constituents thereof over time (e.g., the homogeneity of the composition 
is maintained for an extended period of time) and/or the padding devices 
incorporating flowable material compositions exhibit a certain degree of 
flame retardancy (e.g., based upon the flowable material composition 
having such flame retardancy and/or based upon a synergistic interaction 
between the flowable material (e.g., using halogenous beads in combination 
with antimony trioxide) and envelope structure). 
One aspect of the present invention relates to flame retardancy. In this 
regard, certain constituents of flowable materials in accordance with the 
present invention may be flammable to a certain degree. In order to extend 
the uses of flowable materials to additional applications, such as in 
automotive and/or airplane seat cushions as noted above, it may be 
desirable to provide some degree of flame retardancy (e.g., have the 
flowable material be non-flammable and/or incorporate flame/smoke 
suppressants and/or retardants). Generally, one alternative is to 
incorporate a flame retardant as a constituent of the flowable material. 
Another alternative is to utilize a base liquid for the flowable material 
composition which is itself flame retardant (e.g., a brominated phthalate 
ester such as those marketed under the trademark "Pyronil 45" by Penwalt 
Corporation, 900 First Avenue, King of Prussia, Pa. 19406-0018, and 
hexafluoropropylene epoxide polymers such as those marketed under the 
trademark "Krytox" by Dupont, 1007 Market Street, Wilmington, Del. 19898. 
Furthermore, in the event that a halogen is incorporated into the 
enclosure or envelope structure which contains the flowable material for a 
human anatomy padding application and/or in the event that 
halogen-containing beads are utilized in the flowable material composition 
(e.g., polyvinylidene-dichloride beads such as M6001AE beads from Pierce & 
Stevens Corp. and as further discussed below), a synergistic flame 
retardant (e.g., antimony oxide, zinc stannate) which "reacts" with the 
halogen may be selected to provide a desired degree of flame retardancy. 
In each of the foregoing instances, a certain degree of flame retardancy 
can also be effected by selecting a flame-retardant enclosure material for 
containing the flowable material composition (e.g., polyvinyl chloride 
("PVC"), polyvinylidene dichloride ("PVDC")). Moreover, a flame retardant 
cover may be positioned over the flowable material-containing envelope, 
such as one formed from aramid fibers marketed under the trademark 
"Nomex". 
As noted above, a flame retardant may be incorporated as a constituent of 
the flowable material. In this regard, flame retardants such as boric 
oxide (B.sub.2 O.sub.3), boric acid (B(OH).sub.3) , borax (Na.sub.2 
B.sub.4 O.sub.7.1OH.sub.2 O) , bicarbonate of soda (NaHCO.sub.3), epsom 
salts (MgSO.sub.4.7H.sub.2 O), alumina trihydrate (Al.sub.2 O.sub.3 
3H.sub.2 O or Al(OH).sub.3), chloroparaffins, chlorinated polyethylenes, 
halogens, "Pyronil 45", hydrated calcium carbonate, halogenated fluids 
(e.g., decabromodiphenyl oxide), or mixtures thereof may be added to the 
flowable, pressure-compensating material composition. Moreover, 
phosphonate esters or other char-forming constituents may be utilized. 
Bicarbonate of soda and epsom salts are preferred flame retardants for use 
in certain compositions. Both compounds have the advantage of releasing a 
non-volatile and non-oxygenating gas or water when heated, thereby 
smothering flames. For example, epsom salts will release a quantity of 
steam when heated. Bicarbonate of soda advantageously creates a char 
by-product when contacted with a flame that also increases flame 
retardancy, releases carbon dioxide gas when heated, and has low toxicity. 
Moreover, it has also been found that bicarbonate of soda and epsom salts 
blend easily and thoroughly with certain compositions. 
If boric oxide, boric acid or borax is used as a flame retardant with a 
pressure-compensating composition containing glycerin, silicone oil, or a 
wax/oil composition, the flame retardant is preferably added in an amount 
from about 5 weight percent to about 15 weight percent based on the total 
composition, more preferably from about 7 weight percent to about 8 weight 
percent based on the total composition. 
If bicarbonate of soda or epsom salt is used as a flame retardant, each is 
preferably added in an amount from about 5 weight percent to about 30 
weight percent, more preferably from about 10 weight percent to about 25 
weight percent, most preferably from about 15 weight percent to about 20 
weight percent. 
The flame retardant can be utilized in flowable, pressure-compensating 
compositions that contain a flammable material as noted above. Examples of 
such compositions include wax/oil compositions, silicone oil-containing 
compositions and glycerin-containing compositions. Each of these 
compositions may include beads or substantially spherical particles 
dispersed substantially throughout the composition to influence flow 
characteristics, reduce weight, and/or provide load-carrying capabilities, 
as well as preservatives to prevent/inhibit microbiological attack and/or 
chemical degradation of the flowable material composition. 
As used herein, the term "glycerin" refers to the trihydric alcohol having 
the chemical formula (CH.sub.2 OH).sub.2 CHOH, which is also commonly 
referred to as glycerol. Although glycerin is the preferred alcohol for 
use in connection with the present invention, alternative alcohols such as 
other glycerols (i.e., other trihydric alcohols and also including 
polyhydric alcohols) and glycols (i.e., dihydric alcohols) can also be 
employed. Glycerin has a hygroscopic nature and may comprise a small 
amount of water, e.g., about 4 percent. In certain instances, it is 
advantageous to include an amount of added water in the liquid. 
As used herein, the term "silicone oil" refers to a silicone-based polymer 
with substantially no cross-linking. Such a polymer has substantially no 
memory or is breakable with a relatively low shearing force. Silicone oil 
can be distinguished from silicone gel in that silicone gel has memory. 
One example of a silicone oil is FL200, available from Dow Corning 
Corporation, Midland, Mich. 
As used herein, the term "wax and oil" or "wax/oil" refers to a combination 
of wax and oil such that the wax and oil component present in the 
composition preferably has a density of from about 0.5 to about 1.0 g/cc, 
or, more preferably, from about 0.75 to about 0.90 g/cc. When wax/ oil 
compositions are utilized, the wax preferably ranges in an amount from 
about 40 weight percent to about 69.3 weight percent, while the oil 
preferably ranges from about 1.7 weight percent to about 30 weight 
percent. If beads are utilized in the wax/oil composition, the beads are 
preferably present in an amount less than about 30 weight percent. 
However, in certain flowable material compositions the amount of beads may 
be significantly higher (e.g., 10% oil and 90% acrylonitrile, 
polyvinylidene-dichloride, or phenolic beads as discussed further below). 
The wax component, for example, can be a suitable natural, mineral, 
petroleum-based synthetic, vegetable, or animal wax including insect wax 
such as beeswax [for example, SC 10979 beeswax (yellow), available from 
Sargent-Welch Scientific Co., Skokie, Ill.], paraffin wax, 
microcrystalline wax or paraffin-based waxes. The added or separate oil 
component of the material may be a suitable natural, synthetic, vegetable, 
mineral (including petroleum-derived oils), or petroleum-based oil (for 
example, neutral blending or bright stock). 
In order to facilitate control of the flow characteristics of a finished 
wax/oil material, it is important to avoid the use of unsaturated natural 
or vegetable drying or semi-drying oils that are unsaturated in such a 
manner or to such a level as to oxidize, thicken or harden significantly 
(e.g., polymerize or cross-link) with time or conditions of storage or 
use, which in many instances is reflected by the oil having an excessively 
high or unsatisfactory iodine number. 
With regard to flowable material compositions in accordance with the 
principles of the present invention, as noted above some of such 
compositions may be glycerin-containing and silicone oil-containing 
compositions which incorporate certain viscosity-increasing agents. The 
process for producing the glycerin-containing or silicone oil-containing 
compositions generally involves mixing the liquid, viscosity-increasing 
agent, and, if desired, the flame retardant until a homogenous mixture is 
achieved. Preferably, spherical particles can also be included. The 
specific process for producing compositions in accordance with the present 
invention will vary slightly depending upon the liquid and 
viscosity-increasing agent employed. For example, one process is 
preferably employed when guar, agar, carboxymethylcellulose ("CMC)", 
hydroxypropylcellulose, hydroxyethylcellulose ("HEC") and/or 
polyethyleneoxide (hereinafter collectively referred to as "organic 
viscosity-increasing agents") are employed. A slightly different process 
is employed when fumed silica and/or attapulgite or bentonite clays 
(hereinafter collectively referred to as "mineral viscosity-increasing 
agents") are employed. When the organic viscosity-increasing agents are 
employed, the pH of the composition can be adjusted in order to control 
the rate in which the viscosity of the fluid increases, i.e. the 
"viscosity buildup" rate. Generally, if the pH is lowered, the viscosity 
buildup will proceed at a slower rate as when using CMC's, HEC's or 
cellulosic thickeners. A low pH is also advantageous when using certain 
preservatives in the composition. 
The viscosity-increasing agent is a material which, when mixed with the 
liquid, increases the viscosity of the liquid. Preferred organic 
viscosity-increasing agents for use with the present composition include 
gums, cellulose-based materials and other polymers. Preferred 
viscosity-increasing agents of this type include guar, agar, 
hydroxyethylcellulose, carboxymethylcellulose, hydroxypropylcellulose and 
polyethyleneoxide. Another organic viscosity-increasing material is a pulp 
marketed under the trademark "Kevlar" and it may be desirable for use in 
flowable material compositions of the present invention since it may 
impart a further degree of flame retardancy since it is itself 
non-flammable. Preferably, the organic viscosity-increasing agent is 
present in an amount from about 0.5 weight percent to about 10 weight 
percent, and more preferably from about 1 weight percent to about 6 weight 
percent, and most preferably from about 1.2 weight percent to about 4 
weight percent, based on the total composition weight. 
Hydroxyethylcellulose, carboxymethylcellulose and hydroxypropylcellulose, 
as well as other cellulose-based materials, are available from Aqualon 
Company of Wilmington, Del. Carboxymethylcellulose is described in a 
report entitled "Aqualon (TM) Cellulose Gum, Sodium 
Carboxylmethylcellulose, Physical and Chemical Properties" copyright 
1988, available from Aqualon Company. Hydroxyethylcellulose is described 
in a report entitled "Natrosol (TM), Hydroxyethylcellulose, A Non-Ionic 
Water-Soluble Polymer, Physical and Chemical Properties," revised July 
1987, available from Aqualon Company. Both of these Aqualon publications 
are incorporated herein by reference in their entirety. 
When using organic viscosity-increasing agents such as 
hydroxyethylcellulose, it is preferable that the organic material does not 
include a hydrolyzing retardant layer on its surface, as many commercially 
available brands do. A hydrolyzing retardant layer slows down the 
viscosity-increasing process. When glycerin is utilized in the 
composition, the process can become too slow to be practical. 
The preferred liquids for use together with organic viscosity-increasing 
agents in the present composition include water and glycerin. An important 
advantage gained from the use of water is that it increases the flame 
retardancy of the composition. An important advantage gained from the use 
of glycerin is that it lowers the freezing point of the liquid. 
Additionally, another important advantage gained from the use of glycerin 
is that it is much easier to contain within a resinous package, because 
glycerin is much less likely to evaporate through the resinous material 
than is water. An additional advantage gained from the use of glycerin 
with organic viscosity-increasing agent is that it provides a "viscosity 
bonus effect", described below 
When utilizing organic viscosity increasing agents, the glycerin is 
preferably present in an amount in the range of from about 42 weight 
percent to about 74 weight percent based on the total composition, more 
preferably in an amount from about 57 weight percent to about 69 weight 
percent of the total composition. Water is preferably present in an amount 
in the range from about 1 weight percent to about 8 weight percent based 
on the total composition, more preferably in an amount from about 2 weight 
percent to about 6 weight percent of the total composition. 
The behavior of some viscosity-increasing agents, such as highly 
substituted carboxymethylcellulose, in mixed-solvent systems, such as 
glycerin/water, is similar to its behavior in water alone. However, in 
mixed systems, the viscosity of the solvent affects the viscosity of the 
solution. For example, if a 60:40 mixture of glycerin and water (which is 
10 times as viscous as water alone) is used as the solvent, the resulting 
solution of well-dispersed carboxymethylcellulose will be ten times as 
viscous as the comparable solution in water alone. This behavior is 
commonly referred to as the "viscosity bonus effect." 
The total liquid content in the organic viscosity-increasing agent 
composition is preferably in the range of from about 50 weight percent to 
about 76 weight percent based on the total composition weight, and is more 
preferably present in an amount from about 60 weight percent to about 70 
weight percent. 
The organic viscosity-increasing agent containing composition is preferably 
produced by initially mixing the organic viscosity-increasing agent and 
glycerin. This slurry can then be mixed with water and the remainder of 
the ingredients. Preferably the mixing is accomplished in a blender using 
an emulsifier or homogenization head. As will be appreciated by those 
skilled in the art, other mixing techniques can be employed. 
In addition to organic viscosity-increasing agents, it is possible to use 
mineral viscosity-increasing agents in flowable material compositions of 
the present invention. Preferred mineral viscosity-increasing agents 
include fumed silica, such as Cab-O-Sil M5.TM., available from the Cabot 
Corporation of Tuscola, Ill., attapulgite clays, such as Attagel 40.TM. or 
Attagel 50.TM., both available from the Englehard Corporation of 
Attapulgus, Ga., and bentonite, such as Baragel 3000 or Bentone LT, 
available from Rheox, Inc. of Hightstown, N.J. Advantages of some mineral 
viscosity-increasing agents in general include: the agents can be used 
with glycerin or silicone oil alone, without any need to employ water; the 
composition can be sealed within a resinous package using heat-sealing or 
RF sealing techniques which provide good clean seals; and the materials, 
particularly attapulgite clays, are relatively inexpensive. The advantage 
of using glycerin or silicone oil alone, with no added water, is that a 
composition is obtained having a very low freezing point and in addition, 
it is much easier to contain such liquids within a resinous package. 
Additionally, it has been found that mineral viscosity-increasing agents, 
particularly attapulgite clay, have relatively stable viscosity 
characteristics over a wide range of temperatures and are not prone to 
separating during use. 
The mineral viscosity-increasing agents are preferably present in an amount 
from about 2 weight percent to about 30 weight percent, based on the total 
composition weight. More preferably the mineral agents comprise from about 
3 weight percent to about 20 weight percent of the total composition 
weight, and most preferably from about 4 weight percent to about 15 weight 
percent of the total composition weight. Silicone oil or glycerin employed 
in connection with the mineral viscosity-increasing agents is preferably 
present in an amount from about 25 weight percent to about 75 weight 
percent, and more preferably in an amount from about 50 weight percent to 
about 74 weight percent, based on the total composition weight. When fumed 
silica is employed, as well as attapulgite and/or bentonite clays, it may 
be preferable to also employ a surfactant, e.g. Triton X-100.TM. available 
from Rohm & Haas, Philadelphia, Pa. 19105 and in an amount ranging from 
about 1% to about 5% of the total weight of the composition. However, any 
surfactant with the suitable hydrolyphic balance which lends itself to 
thickening the liquid being used (e.g., oil, glycerin, polyhydroxyl 
alcohols, silicone, flame retardants), which may or may not incorporate 
water in their formulations in either a free or emulsified state, may be 
utilized. 
When mixing the mineral viscosity-increasing agents with the glycerin or 
silicone oil, it is preferable to mix a portion of the glycerin or 
silicone oil with the mineral viscosity-increasing agents to form an 
initial slurry and then add the rest of the materials. The mixing can be 
accomplished using a blender with an emulsifier or a homogenization head. 
Alternatively, all of the materials may be mixed together at once. 
All of the viscosity-increasing agents associated with the present 
invention have the important characteristic of increasing the viscosity of 
a fluid, while still permitting the fluid to flow. The typical composition 
of the present invention is flowable and does not have total memory. In 
other words, once deformed, it will not always return to its original 
shape. However, some compositions in accordance with the present invention 
can exhibit a small degree of gel strength. The gel structure can be 
broken merely by applying a small but sufficient force. 
The compositions of the present invention are non-Newtonian, because their 
viscosities change when the shear rate changes. In other words, the ratio 
of shear rate (flow) to shear stress (force) is not constant. The 
compositions are typically either pseudoplastic or thixotropic. A 
pseudoplastic composition is one which appears to have a yield stress 
beyond which flow commences and increases sharply with an increase in 
stress. In practice, the compositions exhibit flow at all shear stresses, 
although the ratio of flow to force increases negligibly until the force 
exceeds the apparent yield stress. The flow rate of a thixotropic 
substance increases with increasing duration of agitation as well as with 
increased shear stress. In other words, the flow rate is time dependent. 
When agitation is stopped, internal shear stress can exhibit hysteresis. 
Upon re-agitation, less force is generally required to create a given flow 
than is required for the first agitation. The fact that the present 
materials flow more readily when higher shear stress is applied is 
advantageous in a number of applications. 
The beads or particles preferably employed in the present invention are 
preferably spherical and hollow to lessen their density and lighten the 
overall weight of the flowable, pressure-compensating composition, or, if 
desired, can be solid or cellular. Expandable microbeads, as described in 
U.S. Pat. Nos. 4,243,754, 4,108,928, and 4,038,762 can also be employed. 
The beads/particles may be made from a number of suitable materials 
including for example silica glass, saran polymer, phenolic resin and 
carbon. More generally, the beads/particles may be "resinous" that is 
formed from various "plastic" materials. Detailed descriptions of suitable 
beads/particles can be found in the flowable, pressure-compensating 
material patents, described hereinabove and incorporated herein by 
reference in their entirety. Glass beads are preferred in certain 
applications because of their relatively low cost. When higher bead 
strength is desired, plastic, phenolic resin, ceramic, or carbon beads are 
preferred. Acrylonitrile and/or polyvinylidene dichloride beads or 
balloons have the advantage of low weight and high resistance to shear as 
well as high hydrostatic strength. 
When used in compositions where a low total weight is desired, the 
beads/particles are preferably within the size range of from about 10 
micrometers to about 300 micrometers in diameter. The density of spherical 
particles can be, for example, from about 0.05 to about 0.70 grams per 
cubic centimeter. More particularly, glass spherical particles preferably 
have a density of from about 0.23 grams per cubic centimeter to about 0.37 
grams per cubic centimeter and phenolic resin spherical particles 
preferably have a density of about 0.15 grams per cubic centimeter. 
Specific examples of suitable spherical particles include "3M Glass 
Bubbles" available from 3M, St. Paul, Minn., and "Microballoons" available 
from Union Carbide Specialty Chemicals Division, Danbury, Conn. 
Generally, spherical particles are preferably present in an amount from 
about 0.01 to about 32 weight percent based on the total composition 
weight, and more preferably in an amount from about 15 to about 31 weight 
percent and still more preferably in amount from about 25 weight percent 
to about 30 weight percent. 
The spherical particles of the present composition perform at least two 
important functions. First, the size, shape and quantity of the spherical 
particles influence the flow characteristics of the composition. 
Therefore, a composition can be tailored to have the desired flow 
characteristics by selecting the appropriate size, shape and amount of 
particles. Second, because of particle-to-particle contact, the spherical 
particles can enhance the distribution of loads placed on flexible 
packages containing the present composition. 
Another advantage of the spherical particles employed in the present 
invention is that they permit a degree of weight control. For example, in 
most applications, the composition should weigh as little as possible. In 
such instances, lightweight hollow particles are preferred, in order to 
lower the overall density of the composition. However, in some 
applications a heavier composition is desired. Examples of such 
applications include weight belts to be strapped around parts of a 
person's body (e.g., wrist and ankle weights) and padding devices where it 
is desired that the device's own weight hold it firmly in place. When 
heavy compositions are desired, solid particles comprising dense materials 
are preferred. In such applications, particles greater than 300 
micrometers in diameter can be used effectively. 
When employed in padding devices, the flowable, pressure-compensating 
composition is generally enclosed within a flexible, protective enclosure 
with a predetermined volume of the composition retained therein. 
Preferably, the enclosure is formed of suitable flexible material and 
desirably is a pliable, thermoplastic, resinous film that can be 
heat-sealed after the composition is inserted therewithin. Because of 
their relatively low cost and desirable strength and flexibility 
characteristics, polyurethane and polyvinylchloride materials are 
preferred for use as the enclosure film. Polyvinyl chloride material 
provides the further advantage of being flame retardant/nonflammable to a 
certain degree. Knit weave fabric such as aramid fibers marketed under the 
trademark "Nomex" may be used to form a cover which may be positioned over 
the flowable material-containing envelope structure to provide and/or 
enhance flame retardancy. Moreover, certain barrier films may be utilized. 
As noted above, an alternative to achieving flame retardancy relating to 
the use of flowable material compositions in human anatomy padding 
applications is to utilize an enclosure formed from a material containing 
a halogen in combination with a synergistic flame retardant/ smoke 
suppressant As used herein, "synergistic flame retardant/smoke 
suppressant" means the combination of a flame retardant material (e.g., 
halogenated material) and a synergist (e.g., antimony oxide) in a given 
proportion to give rise to a degree of flame retardancy which would exceed 
that degree of flame retardancy if either was used alone. Examples of 
appropriate enclosure materials containing halogens for this type of flame 
retardancy include PVC, halogenated TPE (thermoplastic elastomers). 
Appropriate synergistic flame retardants include antimony oxide and zinc 
stannate. One particularly desirable combination includes an enclosure 
material formed from PVC in combination with zinc stannate as a 
synergistic flame retardant/smoke suppressant. 
The flowable material compositions are initially distributed substantially 
uniformly throughout the confines of the enclosure, which is typically 
provided by sealing (e.g., heat sealing, RF sealing) the film along the 
marginal edges. If desired, one can choose to seal the protective 
enclosure for the composition, but leave a small vent opening and a small 
filling port, so that a predetermined volume of the flowable composition 
may be injected into the enclosure through the filling port, followed by 
sealing both the vent opening and the filling port (e.g., by heat or using 
RF energy). Alternatively, the composition may be placed on one sheet, a 
second sheet may be placed over the composition, and the outer edges 
sealed. As can be appreciated, internal sealing lines can also be formed 
to compartmentalize the composition within the enclosure. 
One of the advantages of using mineral viscosity-increasing agents such as 
fumed silica or attapulgite clays as the viscosity-increasing agent, is 
that the sealability of the film package may be improved. When using 
cellulose based materials as the viscosity-increasing agent, such as 
hydroxyethylcellulose, or when using certain bentonite clays (e.g., 
Baragel 3000), the composition may "plate-out" and contaminate the seal. 
The desired final viscosity of the composition can be selected to suit a 
wide variety of applications. Some applications require high viscosity 
compositions and others require compositions of much lower viscosity. For 
use in padding devices, viscosities in the range of from about 30,000 
centipoise to about 1,000,000 centipoise are preferred. When the viscosity 
exceeds 1,000,000 centipoise, the composition is often so viscous that it 
is difficult to mix and striation of the composition may occur. 
In compositions containing water, the viscosity may generally provided by 
hydrogen bonding between water and the viscosity-increasing agents. This 
hydrogen bonding is generally sufficient to keep the spherical particles 
dispersed throughout the composition. In prior art materials, such as a 
silicone gel disclosed in U.S. Pat. No. 4,380,569, cross-linking reactions 
were believed necessary to prevent the microbeads from floating out. 
In a preferred embodiment of the present invention, steps can be taken in 
order to prevent or at least inhibit microbiological attack and chemical 
degradation of the present compositions. For example, radiation 
sterilization can be performed. Preferably, the composition is subjected 
to radiation such as x-ray radiation or gamma radiation in order to 
destroy microorganisms present in the composition. An advantage of 
radiation treatment is that it can be performed after the composition has 
been placed in a package, such as between pliable sheets of resinous 
material. 
An alternative method useful in preventing/inhibiting microbiological 
attack is the use of a heat sterilization step. For example, a padding 
device comprising the present composition placed in a polyvinylchloride 
package can be heated to about 180.degree. F. for more than about 30 
minutes, preferably between about 30 and 45 minutes. Preferably, this 
method is employed in an autoclave having a nitrogen atmosphere. 
Alternatively, additives can be added to the composition in order to 
inhibit microbiological attack and chemical degradation. Examples of 
suitable preservatives include formaldehyde, methyl- and propylparabens, 
phenol, phenylmercuric salts, sodium benzoate, sodium propionate, sorbic 
acid and sorbates (sodium and potassium salts). Additionally, proprietary 
preservatives such as Busan 11 ml, 85 available from Buckman Laboratory, 
Dowicide A and Dowicil 75, 200 available from The Dow Chemical Company, 
Proxel GXL and CRL available from ICI Americas Inc., Merbac 35 and 
Tektamer 38 available from Merck/Calgon Corporation, Thimerosal available 
from Eli Lilly and Company and Vancide TH available from R. T. Vanderbilt 
Co., Inc. can be used. 
In order to function properly, certain preservatives (e.g. benzoates and 
sorbates) require a low pH, i.e., acidic, environment. This can be 
achieved by adding an acid, e.g. citric acid to the composition. Citric 
and/or other desirable acid is added in an amount sufficient to lower the 
pH to a range of about pH 4 to about pH 6 and preferably about pH 4.5 to 
about pH 5.5. In certain instances, such as when silica glass particles 
are employed, the silica will raise the pH of the system. Therefore, more 
acid is generally necessary to achieve the desired pH range than for a 
composition not having silica particles. Preferably from about 0.1 weight 
percent to about 0.5 weight percent benzoate or sorbate is included in the 
present compositions based on the total composition weight. 
In accordance with the present invention, a process for producing the 
silicone oil- or glycerine-containing compositions is provided. A 
preferred embodiment of the process includes an initial step of producing 
two slurries. For example, a first slurry of a mineral 
viscosity-increasing agent and silicone oil or glycerin or a first slurry 
of organic viscosity-increasing agent and glycerin, and possibly silicone 
oil, can be provided. A second slurry, comprising more liquid, e.g. 
glycerin and/or water or silicone oil, and the spherical particles, is 
then provided. Additives such as acid, preservatives and flame retardants 
can also be mixed with this second slurry. At the appropriate time, the 
two slurries are mixed together. Alternatively, all the components may be 
mixed together at one time. Mixing can take place in mechanical mixers 
such as blenders available from Lightnin and Waring. Alternatively, static 
mixing devices such as those available from Chemix and from Lightnin can 
be used. 
The mixing of flowable material compositions may also include mixing the 
liquid and thickener (e.g., glycerin and attapulgite, oil and fumed 
silica) into a relatively thick or viscous slurry with a homogenization 
head or a "Cowles" dissolver. The slurry may then be thinned with the 
liquid being utilized and the beads may be added. Final mixing may be done 
with a paddle mixer or the like. 
As explained hereinbefore, it can be advantageous to lower the pH of the 
compositions to a range of about pH 4 to about pH 6. One reason for this 
is that the rate of viscosity buildup is slower at lower pH's for organic 
viscosity-increasing agents. This provides a greater amount of time for 
working with the composition before it fully sets up. For example, when 
the composition is placed in an enclosure, it is advantageous if the 
composition maintains a low viscosity for a period of time to allow its 
insertion into the enclosure. The viscosity buildup rate can also be 
slowed by using a low temperature liquid and/or by the use of chemical 
retardants. Alternatively, excess water can initially be employed to lower 
the viscosity. After the composition is placed in the enclosure, excess 
water can be allowed to evaporate until the desired viscosity is attained. 
EXAMPLE NO. 1 
Compositions were prepared containing the following materials: 
______________________________________ 
Weight Percent Material 
______________________________________ 
Composition No. 1 
3.9 Attapulgite Clay (Attagel 
50 .TM. available from 
Englehard Corporation) 
58.1 Glycerin 
28.0 Spherical particles (B-37 
designation for Glass 
Bubbles available from 3M) 
10.0 Bicarbonate of Soda (NaHCO.sub.3) 
______________________________________ 
Actual Weight (Pounds) 
Material 
______________________________________ 
Composition No. 2 
3.4 Glycerin 
0.2 Attapulgite Clay 
1.7 Spherical particles (B-37 
for Glass Bubbles from 3M) 
0.6 Bicarbonate of Soda (NaHCO.sub.3) 
______________________________________ 
Alternatively, epsom salt (MgSO.sub.4.7H.sub.2 O) can be substituted for 
bicarbonate of soda in the above compositions. Both of these formulations 
survived in air aspirated butane torch flame for 20 seconds without 
burning. Both compositions self-extinguished. 
______________________________________ 
Weight Percent Material 
______________________________________ 
Composition No. 3 
75 Silicone Oil (FL200 from 
Dow Corning Corporation) 
25 Spherical particles (B-37 
for Glass Bubbles from 3M) 
______________________________________ 
If desired, a flame retardant and/or a viscosity-increasing material, 
preferably a mineral viscosity-increasing material, can be included in 
Composition 3 of Example 1. 
In addition to the above-identified aspect of the present invention of 
flame retardancy, another aspect of the present invention relates to 
improving upon the maintenance of homogeneity of the flowable material 
composition over a defined period of time/use. Generally, it is desirable 
for the various constituents utilized in flowable material compositions to 
not float and/or settle from remaining portions thereof over an acceptable 
period of time. One way in which the present invention improves upon 
maintaining a desired distribution is to utilize various coupling agents 
in the compositions. As used herein, the phrase "coupling agent(s)" 
therefore means any constituent of a flowable material composition which, 
through some type of bonding and/or interaction with another portion of 
the flowable material composition, reduces the tendency for separation of 
one or more constituents of the flowable material composition. 
One composition of a flowable material in accordance with the above 
generally includes a liquid, a viscosity-increasing material such as clay 
and/or fumed silica, and a plurality of beads having a preselected coating 
thereon and which have a density which is different (typically less) than 
that of both the liquid and the clay. Based on this difference in density, 
the potential exists that the beads will float/separate out from remaining 
portions of the composition. However, the coating on the beads allows 
for/establishes for a "bonding" or coupling effect with the liquid and/or 
the viscosity-increasing material, and thus functions as the coupling 
agent. Therefore, the potential for the beads floating out of or otherwise 
separating from the composition, due to their density in comparison to the 
liquid and clay, is reduced. 
In the above-identified composition, the incorporation of a 
viscosity-increasing component has a viscosity-increasing effect. This may 
be attributed to the surface area of the individual particles of the 
viscosity-increasing material within the liquid and/or a natural affinity 
between the viscosity-increasing material and the liquid (e.g., a polar 
attraction). In the event that the viscosity-increasing material and 
liquid have no natural attraction, it may be desirable to incorporate an 
appropriate surfactant to provide for a coupling of the viscosity 
increasing material and liquid, which would thus further increase the 
viscosity of the flowable material composition if such is desired. 
Appropriate liquids for the above-identified composition include various 
oils, preferably mineral oils and more preferably petroleum-derived oils, 
glycerin-containing solution such as glycerin/water solutions, 
polyhydroxyl alcohol-containing solutions, and appropriate mixtures 
thereof. Depending upon the application and/or other circumstances, it may 
be desirable for the liquid to be all oil or all glycerin, or for the 
liquid to include other constituents therein (e.g., using an oil/wax 
combination or a glycerin/water combination as noted above). Appropriate 
viscosity-increasing materials includes clays such as attapulgites (e.g., 
Attagel 40.TM. or Attagel 50.TM.), bentonites (e.g., Bentone LT), and 
fumed silica (e.g., Cab-O-Sil M5.TM.). Appropriate beads include M6017AE 
beads available from Pierce & Stevens Corp., Buffalo, N.Y. 14240-9990 
(e.g., an acrylonitrile bead having a calcium carbonate coating thereon) 
and M6001AE beads available from Pierce & Stevens Corp. (e.g., a 
polyvinylidene-dichloride bead also having a calcium carbonate coating 
thereon). 
Various combinations of the above-identified types of constituents used in 
a flowable material composition with beads having the preselected coating 
thereon are provided in Example No. 2 below. 
EXAMPLE NO. 2 
______________________________________ 
General Preferred 
Material Volume % Range 
Volume % Range 
______________________________________ 
Composition No. 4 
Attapulgite Clay 
1% to 30% 5% to 15% 
(Attagel 40 .TM. or 50 .TM.) 
Glycerin 10% to 90% 60% to 75% 
(95%-99.9% pure) 
Beads 
(M6001AE, M6017AE) 
10% to 90% 25% to 66% 
Composition No. 5 
Fumed Silica 1% to 20% 5% to 15% 
(Cab-O-Sil M5 .TM.) 
100 PT naphthenic- 
10% to 90% 60% to 75% 
based oil 
Beads 10% to 90% 25% to 66% 
(M6001AE, M6017AE) 
Composition No. 6 
Bentonite 1% to 30% 1% to 10% 
(Bentone LT) 
Glycerin (95%-99.9% 
10% to 90% 60% to 75% 
pure) 
Beads 10% to 90% 1% to 66% 
(M6001AE, M6017AE) 
______________________________________ 
As noted above, in the case of using certain mineral viscosity-increasing 
agents with beads having a calcium carbonate coating thereon, a hydrogen 
bonding between the carbonate coating thereon, a hydrogen bonding between 
the agent and/or liquid and the beads is believed to exist. For instance, 
in the case when Baragel 3000 is used with oil, a surfactant is implanted 
into the surface of the bentonite in the form of a quartenary ammonium 
salt. The hydrogen bonding along the edge of the bentonite platelets 
coupled with the surfactant (quartenary ammonium salt) on the surface of 
the bentonite platelets hydrogen bonds with the H.sub.2 O on the calcium 
carbonate on, for instance, the M6001AE and M6017AE beads to retain such 
within the composition. This phenomenon is also believed to exist to a 
degree when utilizing: attapulgite, glycerin and M6001AE/M6017AE beads; 
bentonite (e.g., Bentone LT which is not surface treated), glycerin, and 
M6001AE/M6017AE beads; or fumed silica, glycerin, and M6001AE/M6017AE 
beads. 
In order to illustrate the effect of using the calcium carbonate coating on 
the beads, one mixture of oil, Baragel 3000, and glass beads (no calcium 
carbonate coating) was compared to a mixture of oil, Baragel 3000, and 
M6001AE/M6017AE beads with the calcium carbonate coating thereon. Although 
the M6001AE and M6017AE beads have a lower specific gravity than the glass 
beads (0.13 g/cc versus 0.37 g/cc), the M6001AE and M6017AE beads appeared 
to float out much less or not at all in extreme temperature oven tests 
(e.g., exposure to a temperature of about 0.degree. F. to 185.degree. F. 
for a time ranging from about 0 months to about 3 months) in comparison to 
the glass beads. 
Generally with regard to the flowable materials of Compositions 4-6 above, 
the viscosity of the flowable material may range from about 10,000 
centipoise to about 1,000,000 centipoise. In the case where oil is the 
only liquid in the compositions, its individual viscosity may range from 
about 40 centipoise to about 400 centipoise to yield a viscosity of about 
10,000 centipoise to about 1,000,000 centipoise for the flowable material 
composition. 
Another way in which homogeneity may be improved/ maintained in flowable 
material compositions is to incorporate an appropriate surfactant. In some 
cases, there may not be any bonding-like interaction/attraction between 
the particular liquid and viscosity-increasing material. The surfactant 
allows for a coupling of the liquid and/or viscosity-increasing material 
and/or beads if used. Consequently, the viscosity of the composition may 
also be increased by adding the surfactant in these instances as well. In 
this case and depending upon the application, it may be desirable to also 
include beads within the flowable material composition. For instance, the 
above-identified beads having the preselected coating thereon to function 
as a coupling agent may be utilized. However, other types of beads may be 
utilized such as the B-37, K-37, K-20, S-32 and/or B-23 beads from 3M 
Corporation (e.g., hollow glass beads). Various combinations of 
constituents incorporating surfactants and which are particularly 
desirable for human anatomy padding applications are provided in Example 
No. 3 below: 
EXAMPLE NO. 3 
______________________________________ 
General Preferred 
Material Volume % Range 
Volume % Range 
______________________________________ 
Composition No. 7 
Attapulgite Clay 
1% to 30% 1% to 15% 
(Attagel 40 .TM. or 
50 .TM.) 
100 PT Motor Oil 
25% to 90% 50% to 75% 
Beads 1% to 90% 5% to 66% 
(K-37, K-20, 
M6001AE, M6017AE) 
Surfactant 1% to 10% 1% to 2% 
(Triton X-100 .TM.) 
Composition No. 8 
Fumed Silica 1% to 20% 1% to 5% 
(Cab-O-Sil M5 .TM.) 
Glycerin 95%-99.9% 
25% to 90% 50% to 75% 
pure) 
Beads 1% to 90% 5% to 66% 
(K-37, K-20, 
M6001AE, M6017AE) 
Surfactant 1% to 10% 1% to 2% 
(Triton X-100 .TM.) 
______________________________________ 
Another combination includes surface treated bentonite (e.g., Baragel 3000 
which is a bentonite clay surface treated with quartenary ammonium salt), 
100 point motor oil and beads (e.g., K-37, K-20, M6001AE, Md6017AE). In 
these cases, the use of the M6000AE/M6017AE beads having the calcium 
carbonate coating thereon may hydrogen bond to the viscosity enhancer 
and/or the liquid. For instance, there may be hydrogen-bonding in a 
composition of attapulgite, oil, M6001AE/M6017AE beads and a surfactant 
between the surfactant, the water on the calcium carbonate coating, and 
the oil. 
Generally, with regard to Compositions 7-8 above for flowable materials in 
accordance with the present invention, the viscosity may range from about 
10,000 centipoise to about 1,000,000 centipoise. In the event that such 
compositions did not include the surfactant, the viscosity would range 
from about 50 centipoise to about 100,000 centipoise. Therefore, under 
some circumstances the viscosity of the flowable material can be 
significantly increased. 
Although the above-identified combinations of constituents for flowable 
material compositions in accordance with the present invention have one or 
more desirable characteristics, other combinations may suitably perform. 
In this case, the following general ranges of constituents may be 
employed: 
______________________________________ 
Material General Volume % Range 
______________________________________ 
Bentonites 1% to 20% 
(e.g., Baragel 3000) 
Attapulgite Clays 1% to 35% 
(e.g., Attagel 40 .TM., 50 .TM.) 
Fumed Silica 1% to 20% 
(e.g., Cab-O-Sil M5 .TM.) 
M6017AE Beads 0% to 100% 
B-37/K-37 Beads 0% to 100% 
Surfactants 1% to 10% 
(e.g., Triton X-100 .TM.) 
Glycerin 0% to 100% 
Oil 0% to 100% 
Flame Retardant Additives 
1% to 20% 
Flame Retardant Base Liquid 
0% to 100% 
______________________________________ 
As noted above, one of the primary applications for flowable materials of 
the type described herein are for use in human anatomy padding 
applications. Referring to FIGS. 1-3, a padding device 10 incorporating a 
flowable material 20 of the present invention is generally illustrated 
therein. The padding device 10 is a substantially pliable enclosure 
generally of the above-identified type and is specifically configured for 
use as a tongue padding device in combination with footwear. In this 
regard, the padding device 10 includes first and second chambers 30, 40 
which are separated by a barrier 50 and fluidly interconnected by a 
passageway 60. Consequently, the padding device 10 effectively pivots 
about the central axis of the instep of the foot 70 of a user when 
positioned thereon such that the first and second chambers 30, 40 are 
positioned on opposite sides of the instep. 
In order to enhance the distribution of the forces applied to the padding 
device 10, such as those forces applied by the tightening of shoe laces or 
velcro straps (not shown), the dimensions of the padding device and/or the 
amount of flowable material 20 contained therein are specifically 
selected. Generally, it is desirable for the shoe laces/velcro straps to 
bridge across the barrier 50 such that all forces applied by such 
laces/straps are communicated to the foot 70 through the flowable material 
20 within the chambers 30, 40. This maximizes the distribution of such 
forces across the foot 70. Moreover, it is preferable to avoid any 
bottoming out when the force is applied to the device 10 (e.g., a total 
migration of flowable material 20 away from an area coinciding with an 
applied force). 
With regard to the dimensions of the padding device 10 and as illustrated 
in FIG. 1, in one embodiment the length "L.sub.1 " of each chamber 30, 40 
ranges from about 2" to about 5" and is preferably about 31/2"; the width 
W.sub.1 of the widest end of each chamber 30, 40 ranges from about 1" to 
about 2" and is preferably about 1"; the width W.sub.2 if the narrowest 
end of each chamber 30, 40 ranges from about 1/4" to about 1" and is 
preferably about 1/2"; the width "W.sub.3 " of the barrier 50 ranges from 
about 1/16" to about 1/4" and is preferably about 1/8"; the length 
"L.sub.2 " of the barrier 50 ranges from about 1" to about 3" and is 
preferably about 2"; and the thickness "T" of each chamber 30, 40 ranges 
from about 1/16 " to about 1/4" and is preferably about 1/8". Moreover, a 
flowable material of any one of the above-described compositions of the 
present invention may be incorporated in an amount ranging from about to 
10 cubic centimeters to about 30 cubic centimeters, and preferably about 
15 cubic centimeters. 
While various embodiments of the present invention have been described in 
detail, it is apparent that modifications and adaptations of those 
embodiments will occur to those skilled in the art. However, it is to be 
expressly understood that such modifications and adaptations are within 
the spirit and scope of the present invention.