(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2004/0234916 A1
`Hale et al.
`(43) Pub. Date:
`NOV. 25, 2004
`
`US 20040234916A1
`
`(54) OPTICALLY IGNITED OR ELECTRICALLY
`IGNITED SELF-CONTAINED HEATING UNIT
`AND DRUG-SUPPLY UNIT EMPLOYING
`SAME
`
`(75)
`
`Inventors: Ron L. Hale, Woodside, CA (US);
`Dennis W. Solas, San Francisco, CA
`(US); Soonho Song, Palo Alto, CA
`(US); Curtis Torn, San Mateo, CA (US)
`
`Correspondence Address:
`ALEXZA MOLECULAR DELIVERY
`CORPORATION
`1001 EAST MEADOW CIRCLE
`PALO ALTO, CA 94303 (US)
`
`(73) Assignee: Alexza Molecular Delivery Corpora-
`tion, Palo Alto, CA
`
`(21) Appl. No.:
`
`10/851,432
`
`(22)
`
`Filed:
`
`May 20, 2004
`
`Related U.S. Application Data
`
`(60) Provisional application No. 60/472,697, filed on May
`21, 2003. Provisional application No. 60/472,697,
`filed on May 21, 2003.
`
`Publication Classification
`
`Int. Cl.7 ..................................................... .. F21K 5/00
`(51)
`(52) U.S.Cl.
`............................................... ..431/358; 431/6
`
`ABSTRACT
`(57)
`Heating units, drug supply units and drug delivery articles
`capable of rapid heating are disclosed. Heating units com-
`prising a substrate and a solid fuel capable of undergoing an
`exothermic metal oxidation reaction disposed Within the
`substrate are disclosed. These heating units can be actuated
`by electrical resistance or by optical ignition. Drug supply
`units and drug delivery articles wherein a solid fuel
`is
`configured to heat a substrate to a temperature sufficient to
`rapidly thermally vaporize a drug disposed thereon are also
`disclosed.
`
`NU MARK Ex.1037 p.1
`
`NU MARK Ex.1037 p.1
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 1 of 22
`
`US 2004/0234916 A1
`
`22
`14
`16
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`NU MARK Ex.1037 p.2
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`NU MARK Ex.1037 p.2
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`

`
`Patent Application Publication Nov. 25, 2004 Sheet 2 of 22
`
`US 2004/0234916 A1
`
`
`
`
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`
`NU MARK Ex.1037 p.3
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`
`84
`88
`
`NU MARK Ex.1037 p.3
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 3 of 22
`
`US 2004/0234916 A1
`
`88
`
`+
`
`90
`
`'
`
`66
`
`62
`
`64
`
`FIG. 2B
`
`NU MARK Ex.1037 p.4
`
`NU MARK Ex.1037 p.4
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 4 of 22
`
`US 2004/0234916 A1
`
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`
`NU MARK Ex.1037 p.5
`
`NU MARK Ex.1037 p.5
`
`
`
`
`
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 5 of 22
`
`US 2004/0234916 A1
`
`FIG. 4A 100
`
`FIG. 4B 200
`
`FIG. 4C 300
`
`FIG. 4D 400
`
`FIG. 4E 500
`
`FIG. 4F 600
`
`NU MARK Ex.1037 p.6
`
`NU MARK Ex.1037 p.6
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 6 of 22
`
`US 2004/0234916 A1
`
`FIG. 5A
`
`
`
`NU MARK Ex.1037 p.7
`
`NU MARK Ex.1037 p.7
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 7 of 22
`
`US 2004/0234916 A1
`
`118
`
`108
`
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`NU MARK Ex.1037 p.8
`
`NU MARK Ex.1037 p.8
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 8 of 22
`
`US 2004/0234916 A1
`
`FIG. 7C
`
`t= 250ms
`
`
`
`FIG. 7D
`
`I: 500ms
`
`FIG. 7E
`
`t = 1000ms
`
`NU MARK Ex.1037 p.9
`
`NU MARK Ex.1037 p.9
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 9 of 22
`
`US 2004/0234916 A1
`
`152
`
`156
`
`150
`
`J
`
`153 air intake
`/
`
`
`
`154
`
`air intake
`
`FIG. 8
`
`NU MARK Ex.1037 p.10
`
`NU MARK Ex.1037 p.10
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 10 of 22
`
`US 2004/0234916 A1
`
`NU MARK Ex.1037 p.11
`
`NU MARK Ex.1037 p.11
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 11 of 22
`
`US 2004/0234916 A1
`
`< 2 «
`
`.5
`
`LL
`
`500
`
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`
`530
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`
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`514
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`516
`
`512
`
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`
`500
`
`516
`
`N
`
`510
`
`NU MARK Ex.1037 p.12
`
`NU MARK Ex.1037 p.12
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 12 of 22
`
`US 2004/0234916 A1
`
`600
`
`/
`
`601 602
`
`640
`
`610
`620
`650
`
`
`
`
`FIG. 11A
`
`
`
`FIG. 11B
`
`NU MARK Ex.1037 p.13
`
`NU MARK Ex.1037 p.13
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 13 of 22
`
`US 2004/0234916 A1
`
`L‘I
`
`II a
`
`0
`
`.1
`!!
`
`0.16
`
`0.18
`
`0.20
`
`0.22
`
`Fuel Mass (g)
`
`
`
`Zr:MoO3 Fuel
`
`550
`
`500
`
`450
`
`-l> O O
`
`350
`
`
`
`
`
`PeakTemperature(°C)
`
`9 80:20 with 0.004" Foil
`
`
`
`A 80:20 with 0.005" Foil
`
`V 70:30 with 0.004" Foil
`
`‘A’ 80:20 with 0.004" Foil
`
`
`
`FIG. 12
`
`NU MARK Ex.1037 p.14
`
`NU MARK Ex.1037 p.14
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 14 of 22
`
`US 2004/0234916 A1
`
`F‘X“o23232""Xa
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`
`218
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`
`FIG. 13C
`
`
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`
`
`NU MARK Ex.1037 p.15
`
`NU MARK Ex.1037 p.15
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 15 of 22
`
`US 2004/0234916 A1
`
`Zr:MoO3 = 80:20 0.004" Foil
`
`*-' 5 GF Mats
`
`— 5 GF Mats
`
`— 3 GF Mats
`
`40
`
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`
`Pressure(psia)
`
`Time (S)
`
`FIG. 14
`
`NU MARK Ex.1037 p.16
`
`NU MARK Ex.1037 p.16
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 16 of 22
`
`US 2004/0234916 A1
`
`
`
`Temperatureaboveambient(°C)
`
`
`
`
`
`Sample 1
`
`—— T1 ---- -- T2 —— T3
`
`Sample 2
`
`: T1 —— T2 — T3
`
`T1: measured beneath fuel
`
`T2: measured between 1st and 2nd mat
`
`T3: measured between 2st and 3rd mat
`
`NU MARK Ex.1037 p.17
`
`NU MARK Ex.1037 p.17
`
`

`
`atent pplication Publication Nov. 25, 2004 Sheet 17 of 22
`
`US 2004/0234916 A1
`
`716 718 713
`
`712
`
`714
`
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`
`714
`
`FIG. 16
`
`NU MARK Ex.1037 p.18
`
`NU MARK Ex.1037 p.18
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 18 of 22
`
`US 2004/0234916 A1
`
`
`
`
`
`PeakPressure(psig)
`
`Peak Temperature (°C)
`
`Zr:MoO3 = 80:20
`
`I 0.004" foil
`
`0 0.005" foil
`
`V 0.005" foil
`
`A 0.004" foil
`
`‘A’ 0.004" foil
`
`Zr:Fe 2 03 = 75:25
`
`FIG. 17
`
`NU MARK Ex.1037 p.19
`
`NU MARK Ex.1037 p.19
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 19 of 22
`
`US 2004/0234916 A1
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`NU MARK Ex.1037 p.20
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`NU MARK Ex.1037 p.20
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`

`
`Patent Application Publication Nov. 25, 2004 Sheet 20 of 22
`
`US 2004/0234916 A1
`
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`
`FIG. 19
`
`NU MARK Ex.1037 p.21
`
`NU MARK Ex.1037 p.21
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 21 of 22
`
`US 2004/0234916 A1
`
`903
`
`FIG. 20A
`
`900
`
`
`
`906
`
`FIG. 20B
`
`NU MARK Ex.1037 p.22
`
`NU MARK Ex.1037 p.22
`
`

`
`Patent Application Publication Nov. 25, 2004 Sheet 22 of 22
`
`US 2004/0234916 A1
`
`‘Z 910
`
`905
`
`FIG. 20D
`
`NU MARK Ex.1037 p.23
`
`NU MARK Ex.1037 p.23
`
`

`
`US 2004/0234916 A1
`
`Nov. 25, 2004
`
`OPTICALLY IGNITED OR ELECTRICALLY
`IGNITED SELF-CONTAINED HEATING UNIT AND
`DRUG-SUPPLY UNIT EMPLOYING SAME
`
`REFERENCE TO RELATED APPLICATIONS
`
`a continuation-in-part and
`[0001] This application is
`claims priority to U.S. provisional application Ser. No.
`60/472,697 entitled “Self-Contained Heating Unit and Drug-
`Supply Unit Employing Same,” filed May 21, 2003, Hale et
`al., the entire disclosure of which is hereby incorporated by
`reference.
`
`FIELD
`
`[0002] This disclosure relates to heating units capable of
`rapid heating and to articles and methods employing such
`heating units.
`
`INTRODUCTION
`
`[0003] Self-contained heat sources are employed in a
`wide-range of industries, from food industries for heating
`food and drink, to outdoor recreation industries for provid-
`ing hand and foot warmers,
`to medical applications for
`inhalation devices. Many self-contained heating sources are
`based on either an exothermic chemical reaction or on ohmic
`
`heating. For example, self-heating units that produce heat by
`an exothermic chemical reaction often have at least two
`
`compartments, one for holding a heat-producing composi-
`tion and one for holding an activating solution. The two
`compartments are separated by a frangible seal, that when
`broken allows mixing of the components to initiate an
`exothermic reaction to generate heat. (see for example U.S.
`Pat. Nos. 5,628,304; 4,773,389; 6,289,889). This type of
`non-combustible, self-heating unit is suitable for heating
`food, drink, or cold toes and fingers, since the heat produc-
`tion is relatively mild.
`
`[0004] Another common source for self-contained heat is
`ohmic heating. In ohmic heating a current is passed through
`an electrically resistive material to generate heat
`that is
`transmitted to an adjacent article. This mode of heat pro-
`duction has been employed to vaporize or heat a volatile
`substance, for example tobacco, for inhalation by a user.
`Cigarette holders and pipe bowls having an electrical resis-
`tance coil to generate heat in order to volatilize tobacco
`flavors have been described (U.S. Pat. Nos. 2,104,266;
`4,922,901; 6,095,143). Heating of drugs other than tobacco
`by ohmic heating have also been described. For example,
`WO 94/09842 to Rosen describes applying a drug to an
`electrically resistive surface and heating the surface to
`vaporize the drug for inhalation. Ohmic heating has the
`advantage of facilitating precise control of the energy
`applied to determine the heat generated. However, in many
`ohmic heating systems, and in particular for small systems
`where limited energy is available, such as, for example,
`when using batteries, there can be a substantial delay on the
`order of seconds or minutes between the time heating is
`initiated and maximum temperature is achieved. Moreover,
`for small devices, such as for example, portable medical
`devices, where the power source comprises a battery, ohmic
`heating can be expensive and bulky.
`
`[0005] Another approach for providing a controlled
`amount of heat is using electrochemical interactions. Here,
`components that interact electrochemically after initiation in
`
`an exothermic reaction are used to generate heat. Exother-
`mic electrochemical reactions include reactions of a metallic
`
`agent and an electrolyte, such as a mixture of magnesium
`granules and iron particles as the metallic agent, and granu-
`lar potassium chloride crystals as the electrolyte. In the
`presence of water, heat
`is generated by the exothermic
`hydroxylation of magnesium, where the rate of hydroxyla-
`tion is accelerated in a controlled manner by the electro-
`chemical interaction between magnesium and iron, which is
`initiated when the potassium chloride electrolyte dissociates
`upon contact with the liquid water. Electrochemical inter-
`actions have been used in the smoking industry to volatilize
`tobacco for inhalation (U.S. Pat. Nos. 5,285,798; 4,941,483;
`5,593,792).
`
`are
`aforementioned self-heating methods
`[0006] The
`capable of generating heat sufficient
`to heat an adjacent
`article to several hundred degrees Celsius in a period of
`several minutes. There remains a need in the art for a device
`
`capable of rapid heat production, i.e., on the order of seconds
`and fractions of seconds, capable of heating an article to
`within a defined temperature range, and which is suitable for
`use in articles to be used by people.
`
`SUMMARY
`
`[0007] Certain embodiments include heating units com-
`prising an enclosure and a solid fuel capable of undergoing
`an exothermic metal oxidation-reduction reaction disposed
`within the enclosure. The solid fuel in these heating units can
`be actuated using a variety of ignition systems.
`
`[0008] Certain embodiments include drug supply units
`comprising an enclosure having at least one substrate having
`an exterior surface and an interior surface, a solid fuel
`capable of undergoing an exothermic metal oxidation-re-
`duction reaction disposed within the enclosure, and a drug
`disposed on a portion of the exterior surface of the substrate.
`
`delivery
`drug
`include
`embodiments
`[0009] Certain
`devices comprising a housing defining an airway, a heating
`unit comprising an enclosure having at least one substrate
`having an exterior surface and an interior surface, and a solid
`fuel capable of undergoing an exothermic metal oxidation-
`reduction reaction disposed within the enclosure, a drug
`disposed on a portion of the exterior surface of the substrate,
`wherein the portion of the exterior surface comprising the
`drug is configured to be disposed within the airway, and an
`igniter configured to ignite the solid fuel.
`
`[0010] Certain embodiments include methods of produc-
`ing an aerosol of a drug and of treating a disease in a patient
`using such heating units, drug supply units, and drug deliv-
`ery devices.
`
`is to be understood that both the foregoing
`It
`[0011]
`general description and the following detailed description
`are exemplary and explanatory only and are not restrictive of
`certain embodiments, as claimed.
`
`DESCRIPTION OF THE DRAWINGS
`
`[0012] FIGS. 1A-1B are cross-sectional illustrations of
`heating units according to certain embodiments.
`
`[0013] FIG. 1C is a perspective illustration of a heating
`unit according to certain embodiments.
`
`NU MARK Ex.1037 p.24
`
`NU MARK Ex.1037 p.24
`
`

`
`US 2004/0234916 A1
`
`Nov. 25, 2004
`
`[0014] FIG. 2A is a cross-sectional illustration of a heat-
`ing unit having a cylindrical geometry according to certain
`embodiments.
`
`[0015] FIG. 2B is a perspective illustration of a heating
`unit having a cylindrical geometry according to certain
`embodiments.
`
`[0016] FIG. 2C is a cross-sectional illustration of a cylin-
`drical heating unit similar to the heating unit of FIGS.
`2A-2B but having a modified igniter design according to
`certain embodiments.
`
`[0029] FIG. 13B is an illustration of a cross-sectional
`view of a cylindrical heating unit having an impulse absorb-
`ing material disposed within the unit.
`
`[0030] FIG. 13C is an illustration of a cross-sectional
`view of a heating unit having an impulse absorbing material
`and an additional pressure reducing element disposed with
`the enclosure.
`
`[0031] FIG. 14 shows the measured pressure within heat-
`ing units comprising glass fiber mats following ignition of
`the solid fuel.
`
`[0017] FIG. 2D is a cross-sectional illustration of a cylin-
`drically-shaped heating unit that includes a thermal shunt
`according to certain embodiments.
`
`[0018] FIG. 3 is a schematic cross-sectional illustration of
`a chemical heating unit having two pressure transducers for
`measuring the internal pressure during and after ignition of
`the solid fuel according to certain embodiments.
`
`[0019] FIGS. 4A-4F are thermal images of a cylindri-
`cally-shaped heating unit measured using an infrared ther-
`mal imaging camera at post-ignition times of 100 millisec-
`onds
`(FIG. 4A), 200 milliseconds
`(FIG. 4B), 300
`milliseconds (FIG. 4C), 400 milliseconds (FIG. 4D), 500
`milliseconds (FIG. 4E), and 600 milliseconds (FIG. 4F)
`according to certain embodiments.
`
`images showing the
`[0020] FIGS. 5A-5B are thermal
`temperature uniformity of the exterior substrate surface
`expanse 400 milliseconds after ignition of two cylindrically-
`shaped heating units according to certain embodiments.
`
`[0021] FIGS. 6A-6C show schematic illustrations of the
`generation of drug vapor from a drug supply unit carrying a
`film of drug on the exterior substrate surface (FIG. 6A);
`ignition of the heating unit (FIG. 6B); and generation of a
`wave of heat effective to vaporize the drug film (FIG. 6C)
`according to certain embodiments.
`
`[0022] FIGS. 7A-7E are high speed photographs showing
`the generation of thermal vapor from a drug supply unit as
`a function of time following ignition of the solid fuel
`according to certain embodiments.
`
`[0023] FIG. 8 shows a drug delivery device containing a
`heating unit as part of an inhalation drug delivery device for
`delivery of an aerosol comprising a drug according to certain
`embodiments.
`
`[0024] FIGS. 9A-9C show drug supply units for use in
`drug delivery devices designed for delivering multiple drug
`doses according to certain embodiments.
`
`[0025] FIGS. 10A-10B show illustrations of a perspective
`view (FIG. 10A) and an assembly view (FIG. 10B) of a thin
`film drug supply unit according to certain embodiments;
`
`[0026] FIGS. 11A-11B show cross-sectional illustrations
`of thin film drug supply units comprising multiple doses
`according to certain embodiments.
`
`[0027] FIG. 12 shows a relationship between the mass of
`a solid fuel coating and the peak temperature of the exterior
`surface of a substrate according to certain embodiments.
`
`[0028] FIG. 13A is an illustration of a cross-sectional
`view of a heating unit having an impulse absorbing material
`disposed within the unit.
`
`[0032] FIG. 15 shows the temperature at various positions
`within a heating unit following ignition of the solid fuel.
`
`[0033] FIG. 16 is a schematic illustration of an igniter
`comprising an initiator composition disposed on an electri-
`cally resistive heating element.
`
`[0034] FIG. 17 shows peak internal pressure within sealed
`heating units following ignition of a thin film layer of solid
`fuel comprising a metal reducing agent and a metal-con-
`taining oxidizer.
`
`[0035] FIG. 18 shows the relationship of the yield and
`purity of an aerosol comprising a specific pharmaceutical
`compound using different substrate temperatures obtained
`from different masses of solid fuel for various embodiments.
`
`[0036] FIG. 19 shows a temperature profile of a heating
`unit substrate following ignition of the solid fuel.
`
`[0037] FIGS. 20A-D are schematic illustrations of various
`embodiments of single dose (FIGS. 20A, B and D) and
`multi-dose (FIG. 20C) heating unit with an optical ignition
`system.
`
`DESCRIPTION OF VARIOUS EMBODIMENTS
`
`[0038] Unless otherwise indicated, all numbers expressing
`quantities of ingredients, reaction conditions, and so forth
`used in the specification and claims are to be understood as
`being modified in all instances by the term “about.”
`
`In this application, the use of the singular includes
`[0039]
`the plural unless specifically stated otherwise. In this appli-
`cation, the use of “or” means “and/or” unless stated other-
`wise. Furthermore, the use of the term “including,” as well
`as other forms, such as “includes” and “included,” is not
`limiting. Also, terms such as “element” or “component”
`encompass both elements and components comprising one
`unit and elements and components that comprise more than
`one subunit unless specifically stated otherwise.
`
`[0040] Heating Unit
`
`[0041] An embodiment of a heating unit is shown in FIG.
`1A. Heating unit 10 can comprise a substrate 12 which can
`be formed from a thermally-conductive material. Thermally-
`conductive materials are well known, and typically include,
`but are not
`limited to, metals, such as aluminum,
`iron,
`copper, stainless steel, and the like, alloys, ceramics, and
`filled polymers. The substrate can be formed from one or
`more such materials and in certain embodiments, can have
`a multilayer structure. For example, the substrate can com-
`prise one or more films and/or coatings and/or multiple
`sheets or layers of materials. In certain embodiments, por-
`tions of the substrate can be formed from multiple sections.
`In certain embodiments, the multiple sections forming the
`
`NU MARK Ex.1037 p.25
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`NU MARK Ex.1037 p.25
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`

`
`US 2004/0234916 A1
`
`Nov. 25, 2004
`
`thermal
`substrate of the heating unit can have different
`properties. A substrate can be of any appropriate geometry,
`the rectangular configuration shown in FIG. 1A is merely
`exemplary. A substrate can also have any appropriate thick-
`ness and the thickness of the substrate can be different in
`
`certain regions. Substrate 12, as shown in FIGS. 1A & 1B,
`has an interior surface 14 and an exterior surface 16. Heat
`can be conducted from interior surface 14 to exterior surface
`
`16. An article or object placed adjacent or in contact with
`exterior surface 16 can receive the conducted heat to achieve
`
`a desired action, such as warming or heating a solid or fluid
`object, effecting a further reaction, or causing a phase
`change. In certain embodiments,
`the conducted heat can
`effect a phase transition in a compound in contact, directly
`or indirectly, with exterior surface 16.
`
`In certain embodiments, heating unit 10 can com-
`[0042]
`prise an expanse of a solid fuel 20. Solid fuel 20 can be
`adjacent to the interior surface 14, where the term “adjacent”
`refers to indirect contact as distinguished from “adjoining”
`which herein refers to direct contact. As shown in FIG. 1A,
`solid fuel 20 can be adjacent to the interior surface 14
`through an intervening open space 22 defined by interior
`surface 14 and solid fuel 20. In certain embodiments, as
`shown in FIG. 1B, solid fuel 20 can be in direct contact with
`or adjoining interior surface 14.
`
`[0043] The components of the solid fuel can react in an
`exothermic reaction to produce heat. For example, the solid
`fuel can react in an exothermic oxidation-reduction reaction
`
`or an intermetallic alloying reaction. An oxidation-reduction
`reaction refers to a chemical reaction in which one com-
`
`pound gains electrons and another compound loses elec-
`trons. The compound that gains electrons is referred to as an
`oxidizing agent, and the compound that loses electrons is
`referred to as a reducing agent. An example of an oxidation-
`reduction reaction is a chemical reaction of a compound
`with molecular oxygen (02) or an oxygen-containing com-
`pound that adds one or more oxygen atoms to the compound
`being oxidized. During the oxidation-reduction reaction, the
`molecular oxygen or the oxygen-containing compound is
`reduced by the compound being oxidized. The compound
`providing oxygen acts as the oxidizer or oxidizing agent.
`The compound being oxidized acts as the reducing agent.
`Oxidation-reduction reactions can be exothermic, meaning
`that the reactions generate heat. An example of an exother-
`mic oxidation-reduction reaction is the thermite reaction of
`
`a metal with a metal oxidizing agent. In certain embodi-
`ments, a solid fuel can comprise a metal reducing agent and
`an oxidizing agent, such as for example, a metal-containing
`oxidizing agent.
`
`In certain embodiments, the metal reducing agent
`[0044]
`and the oxidizing agent can be in the form of a powder. The
`term “powder” refers to powders, particles, prills, flakes, and
`any other particulate that exhibits an appropriate size and/or
`surface area to sustain self-propagating ignition. For
`example, in certain embodiments, the powder can comprise
`particles exhibiting an average diameter ranging from 0.1
`pm to 200 gm.
`
`mony, bismuth, aluminum, and silicon. In certain embodi-
`ments, a metal
`reducing agent can include aluminum,
`zirconium, and titanium. In certain embodiments, a metal
`reducing agent can comprise more than one metal reducing
`agent.
`
`In certain embodiments, an oxidizing agent can
`[0046]
`comprise oxygen, an oxygen based gas, and/or a solid
`oxidizing agent. In certain embodiments, an oxidizing agent
`can comprise a metal-containing oxidizing agent. In certain
`embodiments, a metal-containing oxidizing agent includes,
`but
`is not
`limited to, perchlorates and transition metal
`oxides. Perchlorates can include perchlorates of alkali met-
`als or alkaline earth metals, such as, but not limited to,
`potassium perchlorate
`(KCIO4),
`potassium chlorate
`(KCIO3), lithium perchlorate (LiClO4), sodium perchlorate
`(NaClO4), and magnesium perchlorate [Mg(ClO4)2]. In cer-
`tain embodiments, transition metal oxides that function as
`oxidizing agents include, but are not limited to, oxides of
`molybdenum, such as MoO3, iron, such as Fe2O3, vanadium
`(V205), chromium (CrO3, Cr2O3), manganese (MnO2),
`cobalt (C0304), silver (Ag2O), copper (CuO),
`tungsten
`(W03), magnesium (MgO), and niobium (Nb2O5). In certain
`embodiments,
`the metal-containing oxidizing agent can
`include more than one metal-containing oxidizing agent.
`
`In certain embodiments, the metal reducing agent
`[0047]
`forming the solid fuel can be selected from zirconium and
`aluminum, and the metal-containing oxidizing agent can be
`selected from MoO3 and Fe2O3.
`
`[0048] The ratio of metal reducing agent to metal-contain-
`ing oxidizing agent can be selected to determine the ignition
`temperature and the burn characteristics of the solid fuel. An
`exemplary chemical fuel can comprise 75% zirconium and
`25% MoO3, percentage based on weight. In certain embodi-
`ments, the amount of metal reducing agent can range from
`60% by weight to 90% by weight of the total dry weight of
`the solid fuel.
`In certain embodiments,
`the amount of
`metal-containing oxidizing agent can range from 10% by
`weight to 40% by weight of the total dry weight of the solid
`fuel. In certain embodiments, the amount of oxidizing agent
`in the solid fuel can be related to the molar amount of the
`
`oxidizers at or near the eutectic point for the fuel composi-
`tion. In certain embodiments, the oxidizing agent can be the
`major component and in others the metal reducing agent can
`be the major component. Those of skill in the art are able to
`determine the appropriate amount of each component based
`on the stoichiometry of the chemical reaction and/or by
`routine experimentation. Also as known in the art,
`the
`particle size of the metal and the metal-containing oxidizer
`can be varied to determine the burn rate, with smaller
`particle sizes selected for a faster burn (see, for example,
`U.S. Pat. No. 5,603,350).
`
`In certain embodiments, a solid fuel can comprise
`[0049]
`additive materials to facilitate,
`for example, processing
`and/or to determine the thermal and temporal characteristics
`of a heating unit during and following ignition of the solid
`fuel. An additive material can be reactive or inert. An inert
`additive material will not react or will react to a minimal
`
`In certain embodiments, a metal reducing agent can
`[0045]
`include, but
`is not
`limited to molybdenum, magnesium,
`calcium, strontium, barium, boron,
`titanium, zirconium,
`vanadium, niobium, tantalum, chromium, tungsten, manga-
`nese, iron, cobalt, nickel, copper, zinc, cadmium, tin, anti-
`
`extent during ignition and burning of the solid fuel. An
`additive material can be inorganic materials and can func-
`tion as binders, adhesives, gelling agents, thixotropic agents,
`and/or surfactants. Examples of gelling agents include, but
`are not limited to, clays such as Laponite®, Montmorillo-
`
`NU MARK Ex.1037 p.26
`
`NU MARK Ex.1037 p.26
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`

`
`US 2004/0234916 A1
`
`Nov. 25, 2004
`
`nite, Cloisite®, metal alkoxides, such as those represented
`by the formula R—Si(OR)n and M(OR)n where n can be 3
`or 4, and M can be Ti, Zr, Al, B or other metals, and collidal
`particles based on transition metal hydroxides or oxides.
`Examples of binding agents include, but are not limited to,
`soluble silicates such as Na— or K-silicates, aluminum
`silicates, metal alkoxides, inorganic polyanions, inorganic
`polycations, and inorganic sol-gel materials, such as alumina
`or silica-based sols.
`
`In certain embodiments, the solid fuel comprises
`[0050]
`Laponite®, and in particular Laponite® RDS, as an inert
`additive material. Laponite® is a synthetic layered silicate,
`and in particular a magnesium phyllosilicate, with a struc-
`ture resembling that of the natural clay mineral hectorite
`(NaO_4Mg2_7LiO.3Si4O10(OH)2). Laponite® RD is a com-
`mercial grade material which, when added to water, rapidly
`disperses to form a gel when hydrated (Southern Clay
`Products, Gonzales, Tex.). Laponite® RD has the following
`chemical analysis in weight percent: 59.5% SiO2: 27.5%
`MgO: 0.8% Li2O: 2.8% Na2O. Laponite® RDS (Southern
`Clay Products, Gonzales, Tex.) is a commercially available
`sol-forming grade of Laponiteg modified with a polyphos-
`phate dispersing agent, or peptizer,
`to delay rheological
`activity until the Laponite® RDS is added as a dispersion
`into a formulation. A sol refers to a colloid having a
`continuous liquid phase in which solid is suspended in a
`liquid. Laponite® RDS has the following chemical analysis
`in weight percent: 54.5% SiO2: 26% MgO: 0.8% Li2O: 5.6%
`Na2O: 4.1% P205, In the presence of electrolytes, Lapo-
`nites® can act as gelling and thixotropic agents. Thixotropy
`refers to the property of a material to exhibit decreased
`viscosity under shear.
`
`[0051] When incorporated into a solid fuel composition
`comprising a metal reducing agent and a metal-containing
`oxidizing agent, such as any of those disclosed herein, in
`addition to imparting gelling and thixotropic properties,
`Laponite® RDS can also act as binder. Abinder refers to an
`
`Component
`
`Zirconium (Zr)
`Titanium (Ti)
`Iron (Fe)
`Magnesium (Mg)
`Boron (B)
`Potassium perchlorate
`(KCIO4)
`I.ead Oxide (PbO)
`Tungsten Oxide (WO3)
`Barium Chromate
`
`(BaCrO4)
`Teflon
`
`additive that produces bonding strength in a final product.
`The binder can impart bonding strength, for example, by
`forming a bridge, film, matrix, and/or chemically self-react
`and/or react with other constituents of the formulation.
`
`[0052] An example of the preparation of a solid fuel
`comprising Laponite® RDS and the application of the solid
`fuel to a metal foil substrate are described in Example 1.
`
`In certain embodiments, for example, when the
`[0053]
`solid fuel is disposed on a substrate as a film or thin layer,
`wherein the thickness of the thin layer of solid fuel can
`range, for example, from 0.001 inches to 0.030 inches, it can
`be useful that the solid fuel adhere to the surface of the
`substrate and that the constituents of the solid fuel adhere to
`
`In certain
`integrity.
`each other, and maintain physical
`embodiments,
`it can be useful that the solid fuel remain
`adhered to the substrate surface and maintain physical
`integrity during processing, storage, and use during which
`time the solid fuel coating can be exposed to a variety of
`mechanical and environmental conditions. Several addi-
`
`tives, such as those disclosed herein, can be incorporated
`into the solid fuel to impart adhesion and physical robust-
`ness to the solid fuel coating.
`
`[0054] Other useful additive materials include glass beads,
`diatomaceous earth, nitrocellulose, polyvinylalcohol, and
`other polymers that may function as binders. In certain
`embodiments, the solid fuel can comprise more than one
`additive material. The components of the solid fuel com-
`prising the metal, oxidizing agent and/or additive material
`and/or any appropriate aqueous- or organic-soluble binder,
`can be mixed by any appropriate physical or mechanical
`method to achieve a useful level of dispersion and/or homo-
`geneity.
`In certain embodiments,
`the solid fuel can be
`degassed.
`
`[0055] Tables 1A-1E summarize certain embodiments of
`solid fuel compositions. The weight ratio of the components
`comprising certain solid fuel compositions are provided.
`
`TABLE 1A
`
`Embodiments of Solid Fuel Compositions (wt %)
`
`Fuel #1 Fuel #2 Fuel #3 Fuel #4 Fuel #5 Fuel #6 Fuel #7 Fuel #8
`
`70-90
`
`20-40
`
`20-30
`
`70-92
`
`70-90
`
`20-40
`
`40-60
`
`10-30
`
`8-30
`
`10-30
`
`60-80
`
`20-40
`
`40-60
`
`60-80
`
`70-80
`
`60-80
`
`NU MARK Ex.1037 p.27
`
`NU MARK Ex.1037 p.27
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`

`
`US 2004/0234916 A1
`
`NOV. 25, 2004
`
`[0056]
`
`Component
`
`Zirconium (Zr)
`Titanium (Ti)
`Iron (Fe)
`Aluminum (Al)
`Nickel (Ni)
`Boron (B)
`Potassium perchlorate
`(KCIO4)
`Potassium chlorate (KClO3)
`Tungsten Oxide (WO3)
`Barium Chromate (BaCrO4)
`Zirconium Carbide (ZrC)
`Diatomaceous Earth
`
`[0057]
`
`TABLE 1B
`
`Embodiments of Solid Fuel Compositions Wt %
`Fuel #9
`Fuel #10
`Fuel #11
`Fuel #12
`Fuel #13
`
`Fuel #14
`
`Fuel #15
`
`Fuel #1 6
`
`20-40
`60-80
`
`70-92
`0-84
`
`8-30
`
`60-80
`
`20-40
`
`21
`
`64
`15
`
`55
`
`20
`
`25
`
`10-50
`33-81
`
`9-17
`
`82
`
`18
`
`50
`
`50
`
`TABLE 1C
`
`Embodiments of Solid Fuel Compositions Wt %
`Fuel
`Fuel
`Fuel
`Fuel
`Fuel
`Fuel
`#17
`#1 8
`#19
`#20
`#21
`#22
`
`Fuel
`#23
`
`Fuel
`#24
`
`50-65
`
`0-50
`
`0-50
`
`balance
`
`52.5
`
`47.5
`
`15
`
`20-70
`
`30-80
`
`50-72
`
`30-80
`
`65
`
`55-70
`
`20-70
`
`25-33
`
`85
`
`28-50
`
`25
`
`10
`
`5-12
`
`Component
`
`Zirconium (Zr)
`Titanium (Ti)
`Boron (B)
`Potassium Perchlorate
`(KCIO4)
`Molybdenum Oxide
`(MoO3)
`Iron Oxide
`(F9203)
`Zirconium Hydride
`(ZrH2)
`Diatomaceous Earth
`
`[0058]
`
`TABLE 1D
`
`Embodiments of Solid Fuel Compositions (Wt %)
`
`Component
`
`Zirconium (Zr)
`Titanium (Ti)
`Molybdenum Oxide
`(MoO3)
`Nitrocellulose
`Cab—O—Sil
`Glass Fber
`
`Glass Microsphere
`Polyvinyl Alcohol
`High Vacuum Grease
`
`Fuel
`#25
`
`35-50
`20-35
`30
`
`Fuel
`#26
`
`63-69
`
`27-29.5
`
`4-7.5
`
`Fuel
`#27
`
`Fuel
`#28
`
`Fuel
`#29
`
`Fuel
`#30
`
`Fuel
`#3 1
`
`Fuel
`#32
`
`Fuel
`#33
`
`70
`
`30
`
`excess
`
`34
`
`54
`
`12
`
`66.5-69
`
`66.5-74.6
`
`54-66.5 69
`
`69
`
`28.5-29
`
`24.87—29
`
`28.5—34
`
`29.85 29.85
`
`0.53-4.5
`
`0.5
`
`0.5
`
`0.65
`
`0.65
`
`2.5-4.5
`
`5-12
`
`NU MARK Ex.1037 p.28
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`

`
`US 2004/0234916 A1
`
`Nov. 25, 2004
`
`6
`
`[0059]
`
`Component
`
`Zirconium (Zr)
`Magnesium (Mg)
`Aluminum (Al)
`Silicon (Si)
`Potassium
`chlorate (KCIO3)
`Bismuth Oxide
`(Bizos)
`Molybdenum
`Oxide (M003)
`Diatomaceous
`Earth
`Nitrocellulose
`Glass Beads
`Carboxymethyl
`cellulose
`Polyvinyl alcohol
`40% Aqueous
`sioz
`Viton-A
`
`TABLE 1E
`
`Embodiments of Solid Fuel Compo