Gordon Wardle-- Deflecting Magnetic Shield -- US Patent
Application 20060083831

![](0logo.gif)  
**[rexresearch.com](../index.htm)**

---

**Gordon WADLE // William MAY**

**Deflecting Magnetic Field Shield**

---

**United States Patent 7220488**

**Deflecting Magnetic Field Shield**

**Abstract** --- The present invention concerns a shielding
material for a magnetic shield containing coal slag; silver
powder; a mixture of calcium powder, magnesium powder, and zinc
powder; and silica powder. The shielding material is in powder
form. In another embodiment, the present invention contemplates
adding nano-silver to the shielding material. The present
invention is based on the concept that the magnetic field is
actually "deflected" away from the area shielded. This is
possible in view of the shielding materials used to produce the
magnetic shield.

**Correspondence Name and Address:**

DEFILLO & ASSOCIATES, INC.   
4922 EAGLE COVE SOUTH DRIVE   
PALM HARBOR   
FL 34685 USA

U.S. Current Class:  428/432; 428/457; 428/468; 428/469;
428/688   
U.S. Class at Publication:  428/432; 428/457; 428/469;
428/468; 428/688; Intern'l Class:  B32B 17/06 20060101
B32B017/06; B32B 15/04 20060101 B32B015/04

**TECHNICAL FIELD**

[0001] The present invention concerns a shielding material for
a magnetic field, and more specific to a magnetic shield
containing the shielding material.

**BACKGROUND OF THE INVENTION**

[0002] Magnetic fields are present around all electrical
equipment and power lines. Although we cannot see or feel them,
these fields interact with the components inside the equipments,
causing a slow undulation of displayed images, frequently
described as swimming, shimmy, jitter or even hula, making the
screen illegible. In addition, magnetic interference may
generate incorrect data, operator eyestrain, operator fatigue
and disability.

[0003] Unlike X-rays and light rays, magnetic fields do not
travel in straight lines. Magnetic field lines are continuous
curves, emitting from a source of field and eventually returning
to the point of origin.

[0004] Therefore, shielding is essential in electronic
equipments and various kinds of equipments radiating undesired
magnetic waves; thus, the radiation of the electromagnetic waves
and invasion of the electromagnetic waves from the exterior is
prevented.

[0005] A magnetic shield is traditionally made of a metallic
material such as steel, iron, and nickel. Because metallic
materials have a strong attraction for magnetic fields, the
shield traps the magnetic force and diverts it around the
equipment generating heat. In addition, lead, for example, is
extremely hazardous, heavy, and is very expensive to produce.
Steel requires massive amounts of refinement; it is heavy, and
prone to corrosion. Alloys of steel, iron, copper and nickel are
very expensive to produce and will corrode quickly. Furthermore,
the cost of forming these materials into shapes for current
shielding is high as well as dangerous.

[0006] As components of equipments are made more sensitive,
susceptibility to magnetic waves increases dramatically; thus,
the prior art developed a variety of materials for the shield.

[0007] The prior art shows the use of plates of a metal having
high magnetic permeability and saturation magnetic flux density
such as permalloy. Unfortunately, shields made of this material
are bulky and heavy. In addition, in most of the cases, it is
necessary to cut, bend, or even weld the plates. This is a
laborious and expensive process.

[0008] Furthermore, the prior art shows the use of paramagnetic
materials (e.g. titanium) to encapsulate and shield medical
devices due to their low magnetic susceptibilities. These
materials operate by deflecting electromagnetic fields. However,
although paramagnetic materials are less susceptible to
magnetization than ferromagnetic materials, they can also
produce unwanted images due to eddy currents generated by
externally applied magnetic fields, such as the radio frequency
fields used in the MRI procedures. These eddy currents produce
localized magnetic fields, which disrupt and distort the
magnetic resonance image. In addition, since the paramagnetic
materials are electrically conductive, the eddy currents
produced in them can result in ohmic heating and injury to the
patient or the medical device.

[0009] As steel, iron, and nickel are ferrous materials,
saturation of these materials will occur after a period of time
being exposed to magnetic fields.

[0010] In recent years, Mu-Metal is considered the premier
shielding material for electronic devices. Mu-Metal is the
generic name for a high-permeability, magnetically "soft" alloy
used for magnetic shielding. It includes about 80% nickel and
15% iron, with the balance being copper, molybdenum or chromium,
depending on the recipe being used. Unfortunately, Mu-Metal
material is very expensive. In addition, the Mu-metal contains
ferrous materials; thus, the shield will become saturated,
becoming a magnet itself, to the use of the shield is useless.

[0011] The present inventors have seen the necessity of
providing a magnetic shielding material that overcomes the above
disadvantages. In addition, the present inventors have seen the
necessity of providing a magnetic shield that does not trap the
magnetic forces. Furthermore, the present inventors have seen
the necessity of providing an inexpensive magnetic shielding
material for a magnetic shield.

**SUMMARY OF THE INVENTION**

[0012] It is an object of the present invention to provide a
magnetic shielding material that overcomes the disadvantages of
the shielding materials of the prior art.

[0013] It is an object of the present invention to provide a
magnetic shield that does not trap the magnetic forces.

[0014] It is yet another object of the present invention to
provide a magnetic shield made of a non-metallic, non-ferrous
material.

[0015] It is yet another object of the present invention to
provide substrate having a layer of the non-metallic material
according to the present invention.

[0016] It is yet another object of the present invention to
provide a magnetic shield which is of a simple and economical
construction.

[0017] It is yet another object of the present invention to
provide a lightweight magnetic shield.

[0018] It is yet another object of this invention to provide a
magnetically shielded substrate which is shielded against strong
magnetic fields.

[0019] The present invention concerns a shielding material for
a magnetic shield comprising: [0020] A. coal slag, [0021] B.
silver powder; [0022] C. a mixture of calcium powder, magnesium
powder, and zinc powder; and [0023] D. silica powder.

[0024] The shielding material is in powder form and can be
encapsulated into any form and shape desired.

[0025] The main advantage to the shielding material, according
to the present invention, is this material is non-ferrous. Thus,
the shield will not become saturated, attract a field or become
ineffective.

[0026] The shielding material, according to the present
invention, further contemplates using nano-silver.

[0027] The present invention also relates to a magnetic shield
comprising: [0028] A. a substrate and, disposed above said
substrate, [0029] B. a powdered shielding material comprising:
[0030] C. coal slag, [0031] D. silver powder; [0032] E. a
mixture of calcium powder, magnesium powder, and zinc powder;
and [0033] F. silica powder.

[0034] The substrate may be substantially any size, any shape,
any material, or any combination of materials. The shielding
material(s) disposed on the substrate may be disposed on and/or
in some or all of the substrate.

[0035] Furthermore, the present invention relates to a method
for preparing a powdered shielding material for a magnetic
shield comprising the steps of: [0036] A. providing coal slag;
[0037] B. coating the coal slag with a silver powder; [0038] C.
adding silica powder; [0039] D. adding a mixture of calcium
powder, magnesium powder, and zinc powder.

[0040] Finally, the present invention contemplates adding
nano-silver to the shielding material.

[0041] The magnetic shield of the present invention deflects
the magnetic fields of high power magnets.

[0042] In one embodiment of the present invention, a thin layer
of the shielding material is directly applied onto the surface
of the substrate.

[0043] In another embodiment, the shielding material is
suspended in an appropriate vehicle, and then mixed with
sprayable coating materials.

[0044] The foregoing detailed description is intended to be
illustrative and non-limiting. Many changes and modifications
are possible in light of the above teachings. Thus, it is
understood that the invention may be practiced than as otherwise
specifically described herein and still be within the scope of
the appended claims.

**BRIEF DESCRIPTION OF THE DRAWINGS**

[0045] For a more complete understanding of the nature and
objects of the present invention, reference should be made to
the following detailed description taken together with the
accompanying drawings, in which:

[0046] FIG. 1 shows a side view of the magnetic shield having a
substrate and a layer of the non-ferrous material according to
the present invention.

![](wadle1.jpg)

**DETAILED DESCRIPTION OF THE INVENTION**

[0047] The present invention now will be described more fully
hereinafter with reference to the accompanying drawings, in
which some, but not all, embodiments of the invention are shown.
Indeed, this invention may be embodied in many different forms
and should not be construed as limited to the embodiments set
forth herein; rather, these embodiments are provided so that
this disclosure will satisfy applicable legal requirements. Like
numbers refer to like elements throughout.

[0048] At the present time, the inventors do not understand the
exact reactions that occur when the chemicals are mixed to form
the shielding material of the present invention. The elements
and the order of mixing was only achieved by preconceived notion
and year's of trial and error

[0049] The magnetic shield of the present invention is based on
the concept that the magnetic field is actually "deflected" away
from the area shielded. This is possible in view of the
shielding materials used to produce the magnetic shield.

[0050] The shielding material for a magnetic shield, according
to the present invention, comprises: [0051] A. insulating
material, [0052] B. non-magnetic, non-ferrous material; [0053]
C. a mixture of calcium powder, magnesium powder, and zinc
powder; and [0054] D. inorganic insulating material.

[0055] The shielding material is in powder form and can be
encapsulated into any form and shape desired.

[0056] The following explains the purpose of addition of the
shielding material components and the reasons for limiting the
material compositions.

**Insulating Material**

[0057] The insulating material may be any oxide having
electrically insulating properties. Use may be made of at least
one of oxides of silicon, boron, phosphorus, tin, zinc, bismuth,
alkali metal, alkaline earth metal, germanium, copper, aluminum,
titanium, zirconium, vanadium, niobium, tantalum, chromium,
manganese, tungsten, iron, chromium, cobalt, rare earth metals,
coal slag, and molybdenum which can form a vitreous material.

[0058] The present invention preferably uses coal slag as the
insulation material. Most preferably, the present invention uses
a 30/60 coal slag.

[0059] Coal slag is made from quenched liquid coal slag and
fresh water washed, this product is extremely inert, has a low
moisture content, a high degree of etch for permanent bonding of
coatings, is ready used, is economical, and leaves minimum dust.
Containing virtually no free or crystalline silica, coal slag is
one of the safest and most inexpensive insulation materials.

[0060] Coal slag generally has the following composition:

[0061] SiO.sub.2, preferably in the range of about 20 to 60
weight percent, more preferably in the range of about 40 to 55
weight percent;

[0062] Al.sub.2O.sub.3, preferably in the range of about 10 to
35 weight percent, more preferably in the range of about 15 to
30 weight percent;

[0063] Fe.sub.2O.sub.3 and FeO, preferably in the range of
about 5 to 35 weight percent, more preferably in the range of
about 10 to 20 weight percent;

[0064] CaO, preferably in the range of about 1 to 20 weight;
Na.sub.2O and K.sub.2O, preferably in the range of about 0.1 to
4 weight percent.

[0065] Coal slag has conductivity at 230.degree. C.
(cal/s-cm-.degree. C.) of less than 25 micron Siemens. Thus, the
material may be use as insulator.

[0066] The present invention contemplates using from about 20
to about 50 weight percent of a coal slag, preferably 35 weight
percent.

**Non-Magnetic Material**

[0067] The present invention uses a metal barrier layer to cut
any possible magnetic interaction. The metal barrier layer is
preferably made of a non-magnetic metal material. The
non-magnetic metal material forming the metal barrier layer is
not limited to a specific material, but may be selected from
various kinds of non-magnetic metal materials. However,
particularly preferable materials are: metals, such as Sc, Ti,
Cu, Zn, Y, Zr, Ru, Rh, Pd, Ag, Cd, Re, Os, Ir, Pt, Au, Ti and
Pb, and non-magnetic alloys containing them.

[0068] The present invention preferably uses silver. Most
preferably, a 6.mu. silver powder.

[0069] As known by a person skilled in the art, silver has
sterilizing, anti-microbial, deodorizing, antistatic, and
electromagnetic shielding effects.

[0070] Silver is a lustrous, white metal, more ductile and
malleable than any other metal, excluding gold. Silver is the
best reflector of visible light known until air causes it to
tarnish. In pure air and in water, it is stable.

[0071] The silver powder (damp) is added to improve the
smoothness of the coal slag (dry) and to form the base layer on
the shielding material. Furthermore, the silver powder is added
to the insulation material to make the particle surface
reflective.

[0072] The present invention contemplates using from about 4 to
about 30 weight percent of a silver powder, preferably 15 weight
percent.

**Insulating Inorganic Material**

[0073] The insulating inorganic material used in the surface of
the shielding material is not limited specifically. Any material
may be used if it has electric insulation properties. For
example, silica fine powder or alumina fine powder may be used.
Especially, the silica fine powder is preferably used.

[0074] Silica is noncombustible, colorless or white, tasteless
"crystals". It occurs naturally in the crystalline and amorphous
forms. The specific gravity and melting point depend on the
crystalline form. Silica is known to occur in 17 crystalline
phases or modes and five amorphous phases.

[0075] Of the silica fine powder, spherical silica fine powder,
triturated silica fine powder, granular type silica fine powder,
and the like, may be used. In addition, from the point of view
of fine particle size, the silica fine powder, having an average
primary particle size of 1-1,000 nm, may be used. Especially,
the silica fine powder having 250 sieve screen size is
preferably used.

[0076] The present invention contemplates using from about 15
to about 45 weight percent of a silica powder, preferably 25
weight percent.

**Pharmacy Grade Calcium, Magnesium and Zinc Finely Ground to
a Powder.**

[0077] Any over the counter pharmacy grade calcium, magnesium,
or zinc may be use in the present invention.

[0078] The chemical must be ground to a fine powder before
adding to the shielding material according to the present
invention.

[0079] The present invention contemplates using from about 15
to about 45 weight percent of a mixture of calcium powder,
magnesium powder, and zinc powder, preferably 25 weight percent.

[0080] The mixture of the three chemical contains 60% of
calcium, 28% of magnesium, and 12% zinc. This mixture is
preferably 25% weight of the shielding material according to the
present invention.

**Nano-Material**

[0081] In one embodiment of the present invention, the
invention contemplates coating the shielding material with a
nano-material.

[0082] In general, and as is known to those skilled in the art,
nano-material is material which has an average particle size
less than 100 nanometers and, preferably, in the range of from
about 2 to 50 nanometers.

[0083] The present invention preferably uses nano-silver. Nano
Silver has upgraded beneficial effects of silver by making it
into very small particles of one over one billion meter. This
material is environment-friendly and not toxic.

[0084] The nano-silver has the ability to deflect
electromagnetic fields while remaining electrically
non-conductive.

[0085] The nano-silver, when placed on an object, is capable of
deflecting electromagnetic fields, thereby protecting sensitive
internal components, while also preventing the formation of eddy
currents in the object.

[0086] The present invention contemplates using from about 3 to
about 10 weight percent of nano-silver, preferably 7 weight
percent.

**Magnetic Shield**

[0087] FIG. 1 is a side view of the magnetic shield according
to the present invention. The magnetic shield 10 comprises:
[0088] A. a substrate 20 and, disposed above said substrate,
[0089] B. a shielding material 30 comprising: [0090] C. coal
slag, [0091] D. silver powder; [0092] E. a mixture of calcium
powder, magnesium powder, and zinc powder; and [0093] F. silica
powder.

[0094] The substrate may be substantially any size, any shape,
any material, or any combination of materials. The shielding
material(s) disposed on and/or in such substrate may be disposed
on and/or in some or all of such substrate.

[0095] The actual process for producing the shield material is
very simple and safe. No extreme heat is required. No advanced
mix processing is required.

[0096] In one embodiment of the present invention a thin layer
(in the figure, shown by hatching of dots) of the shielding
material is directly applied onto the surface of the substrate.

[0097] In another embodiment, the shielding material is
suspended in an appropriate vehicle, and then mixed with a
sprayable, brushable, or rollable coating.

[0098] Objects and advantages of this invention are further
illustrated by the following examples, but the particular
materials and amounts thereof recited in these examples, as well
as other conditions and details, should not be construed to
unduly limit this invention. All parts and percentages are by
weight unless otherwise indicated.

**EXAMPLE 1**

[0099] Step 1. 35 grams of 30/60 coal slag was provided. The
coal slag contained 25% Aluminum Oxide, 25% Iron Oxide, and 50%
Mineralized Glass.

[0100] Step 2. The coal slag was coated with 15 grams of a six
micron (6.mu.) silver powder. The silver powder was slightly
moistened and adhered to the coal slag.

[0101] Step 3. Then, 25 grams of white silica powder--250 sieve
screen was added to the top of the silver powder. The silica
powder adhered to the silver powder.

[0102] Step 4. Finally, 25 grams of a mixture of pharmacy grade
calcium, magnesium, and zinc powder. The 25% of the mixture
contains 60% weight of calcium, 28% weight of magnesium, and 12%
weight of zinc.

[0103] The three elements of step 4 are pharmacy grade and were
purchased over the counter at a local drug store in tablet form
and then finely ground.

[0104] Results of the test for example 1:

[0105] A test was done using a 21/2 ounce round spherical
container 3/4'' diameter.times.11/2'' long of iron filings, a 28
lb pull 3/4'' diameter.times.1/2'' long rare earth magnet, and
one 3/8'' thick 4''.times.4'' square sheet of each of the
following materials: [0106] A. Plastic [0107] B. Lead [0108] C.
Stainless Steel [0109] D. Copper [0110] E. the sheet covered
with the shielding material of the present invention.

[0111] The test went as follows:

[0112] Each individual sheet of shielding material was set
upright. The 28 lb rare earth magnet was held against one side
of the shielding material and the iron fillings against the
other side. The magnet and the iron fillings were held against
each side of the shielding material listed above A-E in the same
manner.

[0113] The magnet attraction from the 28 lb magnet to the iron
fillings on shielding sheets A-D was strong enough to hold the
iron fillings and the magnet in place.

[0114] Test results with sheet E. (present invention). The
shield element E deflected the magnetic pull of the 28 lb rare
earth magnet preventing the attraction to the iron fillings,
thus the magnet and the iron filing fall down due the earth
gravitation pull.

[0115] The shielding material is in powder form and can be
encapsulated into any form and shape desired.

**EXAMPLE 2**

[0116] Step 1. 33 grams of 30/60 coal slag was provided. The
coal slag contained 25% Aluminum Oxide, 25% Iron Oxide, and 50%
Mineralized Glass.

[0117] Step 2. The coal slag was coated with 15 grams of a six
micron (6.mu.) silver powder. The silver powder was slightly
moistened and adhered to the coal slag.

[0118] Step 3. Then, 25 grams of white silica powder--250 sieve
screen was added to the top of the silver powder. The silica
powder adhered to the silver powder.

[0119] Step 4. Finally, 20 grams of a mixture of pharmacy grade
calcium, magnesium, and zinc powder. The 25% of the mixture
contains 60% weight of calcium, 28% weight of magnesium, and 12%
weight of zinc. The 20% of the mixture contains 60% weight of
calcium, 28% weight of magnesium, and 12% weight of zinc.

[0120] The three elements of step 4 are pharmacy grade and were
purchased over the counter at a local drug store in tablet form
and then finely ground.

[0121] Step 5. 7 grams of nano-silver were mixed with the
mixture of step 4.

[0122] Results of the test for example 2:

[0123] A test was done using a 21/2 ounce container of iron
filings, a 28 lb pull rare earth magnet, and one 3/8'' thick
4''.times.4'' square sheet each of the following materials:
[0124] A. Plastic [0125] B. Lead [0126] C. Stainless Steel
[0127] D. Copper [0128] E. the sheet covered with the shielding
material of the present invention.

[0129] For the shielding material E, a 1/4'' thick
4''.times.4'' square sheet was used. The sheet thickness was
reduced from 3/8'' to 1/4''. This included the plastic sidewall
that held the shielding material place while testing. Each wall
thickness of about 1/32'' actually decreased the true thickness
of the shielding material to 3/16''. Thus, the actual thickness
of the shielding material on the substrate was at about 1/2 the
thickness of the material that was tested, with the same results
as the first test.

[0130] The test went as follows:

[0131] Each individual sheet of shielding material was set
upright. The 28 lb rare earth magnet was held against one side
of the shielding material, and the iron fillings against the
other side. The magnet and the iron fillings were held against
each side of the shielding material listed above A-E in the same
manner.

[0132] The magnet attraction from the 28 lb magnet to the iron
fillings on shielding sheets A-D was strong enough to hold the
iron fillings and the magnet in place.

[0133] Test results with sheet E. (present invention). The
shield element E deflected the magnetic pull of the 28 lb rare
earth magnet preventing the attraction to the iron fillings;
thus, the magnet and the iron fillings fall down due to the
earth's gravitation pull.

[0134] The shielding material is in powder form and can be
encapsulated into any form and shape desired.

[0135] Adding nano-silver to the mixture of example 1 shows
8-10% improvement for the magnetic field deflection over
original formula mixture.

**EXAMPLE 3**

[0136] The objective of the experiment was to create a static
distortion on a radio.

[0137] An AM radio and another electronic device were set
approximately 12 inches apart.

[0138] An adhesive was sprayed on a plain sheet of paper, and
the shielding material of example 1 was applied to the paper.

[0139] The paper was then lowered between the two devices.

[0140] The result was a very noticeable reduction in the static
on the radio.

[0141] The magnetic shield, according to the present invention,
is of much lighter weight than the ferrous shields of the prior
art.

[0142] The magnetic shield of the present invention may be used
with: [0143] MRI units for shielding of errant and stray fields;
[0144] power transfer for AC power line transformers; [0145]
security installations, conference rooms, command centers, and
test facilities; [0146] electronic equipments such as computers
and other sensitive systems; and [0147] auto industry for
everything from propulsion to electronic protection.

[0148] The main advantage to this shield is that it is
non-ferrous. By being non-ferrous, the shield will not become
saturated and become ineffective. Because of the non-ferrous
makeup of the magnetic shield of the present invention, there
will be no loss of power from the magnet(s) when used next to
the shield.

[0149] In addition, the present invention contemplates the use
of the magnetic shield in outer space. With the magnetic shield
deflecting the magnetic fields towards the core of the earth by
means of gravity, the use in space would be far superior. With
no gravity to deal with, the deflection would not be focused
downward. This may very well create a true "reflection" shield.

[0150] The use of the shielding material in radiological work
has many possibilities. As a deflector of magnetic fields, the
shield could have the same effect on radioactive material as
well. This is a very distinct possibility. Further testing would
be required to establish the impact in this field.

[0151] The major advantage of the magnetic shield of the
present invention is that it is environmentally safe. The shield
itself is formulated from elements that are earth friendly and
will not hurt the environment.

[0152] Many modifications and other embodiments of the
invention set forth herein will come to mind to one skilled in
the art to which this invention pertains, having the benefit of
the teachings presented in the foregoing descriptions and the
associated drawings. Therefore, it is to be understood that the
invention is not to be limited to the specific embodiments
disclosed, and that modifications and other embodiments are
intended to be included within the scope of 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.

---