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US4283427A Expired / Lapsed US ⏱️ 0.0 years remaining

Microwave heating package, method and susceptor composition

Assignee: Pillsbury Co
•
Filing: 1978-12-19
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Granted: 1981-08-11
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Expires: 1998-12-19
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Abstract

Abstract A microwave heating package, and a method of microwave heating. Both the package and the method employ a lossy chemical susceptor which upon continued exposure to microwave radiation becomes substantially microwave transparent, thus building into the system a unique maximum temperature shut off at the point at which the chemical susceptor becomes microwave transparent. The chemical susceptor is comprised of a combination of a solute, such as inorganic salts of Group IA and IIA, and a polar solvent for the solute, such as water. The chemical susceptor may be composed of a hydrated form of the inorganic salts. The package, method and chemical susceptor may be used for microwave heating of many products, including among others, food products.

Inventors

  • 👤 William C. Winters
  • 👤 Hsien-Hsin Chang
  • 👤 George R. Anderson
  • 👤 Ross A. Easter
  • 👤 Jeffrey J. Sholl

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 12:45
CPC Classifications
B; B65; B65D; B65D81/00; B65D81/34; B65D81/3446; B65D2581/00; B65D2581/34; B65D2581/3437; B65D2581/3439; B65D2581/3447; B65D2581/3471; B65D2581/3485; B65D2581/3486; B65D2581/3494

Claims Analysis

Total Claims: 46
Claim 1
Independent Claim 109 words
A lossy susceptor device for microwave energy, which upon continued heating by exposure to microwave radiation has a chemical susceptor portion which becomes substantially microwave transparent, said susceptor device comprising: a chemical susceptor comprising a combination of a solute and a polar solvent for said solute, the amount of solute present being as a minimum an amount which will depress the vapor pressure of said solvent, at least by 25% when compared to said solvent's boiling point at standard pressure; and a holder for said chemical susceptor said holder including vent means which permits escape of solvent from the holder when said chemical susceptor is exposed to microwave radiation.
Claim 2
Dependent Claim 109 words
A lossy susceptor device for microwave energy, which upon continued heating by exposure to microwave radiation has a chemical susceptor portion which becomes substantially microwave transparent, said susceptor device comprising: a chemical susceptor comprising a combination of a solute and a polar solvent for said solute, the amount of solute present being as a minimum an amount which will depress the vapor pressure of said solvent, at least by 25% when compared to said solvent's boiling point at standard pressure; and a holder for said chemical susceptor said holder including vent means which permits escape of solvent from the holder when said chemical susceptor is exposed to microwave radiation.
Claim 3
Dependent Claim 29 words
The chemical susceptor of claim 1 wherein the solute is present in at least a minimum amount sufficient to provide a eutectic mixture of said solute in said solvent.
Claim 4
Dependent Claim 32 words
The chemical susceptor of claim 2 wherein the solute is present in at least a minimum amount sufficient to provide a saturated solution, at room temperature, of said solute in said solvent.
Claim 5
Dependent Claim 26 words
The chemical susceptor of claim 3 wherein the combination of solute and polar solvent is more lossy than either the solute alone or the solvent alone.
Claim 6
Dependent Claim 18 words
The chemical susceptor of claim 3 wherein said vapor pressure of said solvent is depressed at least 50%.
Claim 7
Dependent Claim 20 words
The chemical susceptor of claim 3 wherein said vapor pressure of said solvent is depressed of about 70% or greater.
Claim 8
Dependent Claim 25 words
The chemical susceptor of claim 3 wherein said vapor pressure of said solvent is depressed in the range of between about 70% and about 80%.
Claim 9
Dependent Claim 14 words
The chemical susceptor of claim 3 wherein said solute is an inorganic salt material.
Claim 10
Dependent Claim 25 words
The chemical susceptor of claim 8 wherein said inorganic salts are selected from the group consisting of Groups IA and IIA salts, of mixtures thereof.
Claim 11
Dependent Claim 24 words
The chemical susceptor of claim 9 wherein said salts are Group IA and IIA salts which when mixed with said polar solvent become paste-like.
Claim 12
Dependent Claim 16 words
The chemical susceptor of claim 10 wherein said salts are salts capable of forming water hydrates.
Claim 13
Dependent Claim 15 words
The chemical susceptor of claim 8 wherein said polar solvent for said solute is water.
Claim 14
Dependent Claim 35 words
The chemical susceptor of claim 10 wherein said salts are Groups IA and IIA inorganic salts which significantly increase their solubility in water at 100° C. in comparison with their water solubility at 20° C.
Claim 15
Dependent Claim 15 words
The chemical susceptor of claim 13 wherein said salts are capable of forming water hydrates.
Claim 16
Dependent Claim 15 words
The chemical susceptor of claim 14 wherein said polar solvent for said solute is water.
Claim 17
Dependent Claim 35 words
The chemical susceptor of claim 12 wherein said salts are Groups IA and IIA inorganic salts which significantly increase their solubility in water at 100° C. in comparison with their water solubility at 20° C.
Claim 18
Dependent Claim 32 words
The chemical susceptor of claim 3 wherein said chemical susceptor includes a heating profile modifier in an amount of from about 0.1% by weight to about 25% by weight of chemical susceptor.
Claim 19
Dependent Claim 30 words
The chemical susceptor of claim 17 wherein said heating profile modifier is present at a level of from about 0.2% by weight to about 10% by weight of chemical susceptor.
Claim 20
Dependent Claim 28 words
The chemical susceptor of claim 17 wherein said heating profile modifier is an additive which makes said polar solvent more difficult to remove from said system during heating.
Claim 21
Dependent Claim 13 words
The chemical susceptor of claim 19 wherein said heating profile modifier is hydrophilic.
Claim 22
Dependent Claim 25 words
The chemical susceptor of claim 20 wherein said heating profile modifier is selected from the group consisting of clays, carbohydrates, titanium dioxides, fats, and silicates.
Claim 23
Dependent Claim 21 words
The chemical susceptor of claim 12 wherein said salt comprises from about 30% to about 85% by weight of said susceptor.
Claim 24
Dependent Claim 22 words
The chemical susceptor of claim 22 wherein said salt comprises from about 45% to about 80% by weight of said chemical susceptor.
Claim 25
Dependent Claim 12 words
The chemical susceptor of claim 9 wherein said salt is calcium chloride.
Claim 26
Dependent Claim 12 words
The chemical susceptor of claim 9 wherein said salt is lithium chloride.
Claim 27
Dependent Claim 70 words
The susceptor device of claim 3 wherein said holder includes a pair of sheet members with at least a portion of the one said sheet member being substantially microwave transparent, said chemical susceptor is interposed between the sheet members, said sheet members being secured to one another substantially enclosing the chemical susceptor, vent means for allowing the venting of the solvent from the holder during heating of the chemical susceptor.
Claim 28
Dependent Claim 30 words
The susceptor device of claim 26 wherein both of said sheet members are substantially microwave transparent and said chemical susceptor is adhered to at least one of said sheet members.
Claim 29
Dependent Claim 39 words
The susceptor device of claim 1 wherein said device is positioned adjacent a food product whereby said chemical susceptor is in heat transfer relationship with said food product and will heat said food product upon exposure to micowave radiation.
Claim 30
Dependent Claim 21 words
The susceptor device of claim 1 positioned in a microwave radiation field sufficiently strong to cause said chemical susceptor to heat.
Claim 31
Dependent Claim 15 words
The susceptor device of claim 1 wherein said holder is of a low lossy material.
Claim 32
Dependent Claim 23 words
The susceptor device of claim 1 wherein said holder substantially encloses the chemical susceptor and has at least one substantially microwave transparent portion.
Claim 33
Dependent Claim 19 words
The susceptor device of claim 1 wherein the thickness of the chemical susceptor is up to about 0.1 centimeters.
Claim 34
Dependent Claim 126 words
A lossy susceptor device for microwave energy, which upon continued exposure to microwave radiation has a chemical susceptor portion which becomes substantially microwave transparent, said susceptor device comprising: a low lossy holder for said chemical susceptor, and a chemical susceptor in heat transfer association with said holder comprising an inorganic salt selected from Group IA and Group IIA salts in combination with water as a polar solvent for said salts, and a heating profile modifier, the amount of said salt being sufficient to depress the vapor pressure of water at least by 25% when compared to the vapor pressure of water at standard pressure, said holder including vent means which permits escape of solvent from the holder when said chemical susceptor is exposed to microwave radiation.
Claim 35
Dependent Claim 126 words
A lossy susceptor device for microwave energy, which upon continued exposure to microwave radiation has a chemical susceptor portion which becomes substantially microwave transparent, said susceptor device comprising: a low lossy holder for said chemical susceptor, and a chemical susceptor in heat transfer association with said holder comprising an inorganic salt selected from Group IA and Group IIA salts in combination with water as a polar solvent for said salts, and a heating profile modifier, the amount of said salt being sufficient to depress the vapor pressure of water at least by 25% when compared to the vapor pressure of water at standard pressure, said holder including vent means which permits escape of solvent from the holder when said chemical susceptor is exposed to microwave radiation.
Claim 36
Dependent Claim 34 words
The chemical susceptor of claim 33 which comprises about 45% by weight calcium chloride as the inorganic salt, about 45% by weight and about 10% by weight silica gel as a heating profile modifier.
Claim 37
Independent Claim 172 words
A method of microwave heating products which simultaneously heats internal portions of said product and selectively raises to a higher temperature pre-selected areas of said products, said method comprising: locating a lossy susceptor device in a microwave environment, said susceptor device including a chemical susceptor comprising a solute and a polar solvent for said solute, the amount of said solute being as a minimum an amount sufficient to provide a saturated solution of said solute in said polar solvent and an amount which will depress the vapor pressure of said solvent at least 25% when compared to the vapor pressure of said solvent at its boiling point at standard pressure, placing said product which is to be heated in heat transfer association with at least a portion of said susceptor device, and exposing said susceptor device to microwave radiation energy to heat said chemical susceptor, said chemical susceptor being heated to a higher temperature than said product until said polar solvent is driven off, and thereafter said chemical susceptor becoming substantially non-lossy.
Claim 38
Independent Claim 172 words
A method of microwave heating products which simultaneously heats internal portions of said product and selectively raises to a higher temperature pre-selected areas of said products, said method comprising: locating a lossy susceptor device in a microwave environment, said susceptor device including a chemical susceptor comprising a solute and a polar solvent for said solute, the amount of said solute being as a minimum an amount sufficient to provide a saturated solution of said solute in said polar solvent and an amount which will depress the vapor pressure of said solvent at least 25% when compared to the vapor pressure of said solvent at its boiling point at standard pressure, placing said product which is to be heated in heat transfer association with at least a portion of said susceptor device, and exposing said susceptor device to microwave radiation energy to heat said chemical susceptor, said chemical susceptor being heated to a higher temperature than said product until said polar solvent is driven off, and thereafter said chemical susceptor becoming substantially non-lossy.
Claim 39
Dependent Claim 95 words
A disposable package for use in microwave ovens, said package comprising: a container of substantially non-lossy material for holding of a product to be treated with microwave radiation, and a chemical susceptor for microwave energy associated with said container for thermal contact with at least one surface of a product which is to be placed in said container, said chemical comprising an inorganic salt selected from the group consisting of Group IA and Group IIA salts, and a polar solvent for said salt, and a low lossy substantially microwave transparent holder surface for said susceptor.
Claim 40
Dependent Claim 95 words
A disposable package for use in microwave ovens, said package comprising: a container of substantially non-lossy material for holding of a product to be treated with microwave radiation, and a chemical susceptor for microwave energy associated with said container for thermal contact with at least one surface of a product which is to be placed in said container, said chemical comprising an inorganic salt selected from the group consisting of Group IA and Group IIA salts, and a polar solvent for said salt, and a low lossy substantially microwave transparent holder surface for said susceptor.
Claim 41
Dependent Claim 21 words
The package of claim 36 wherein said package includes on selected surfaces a microwave shield to directionally control the microwave exposure.
Claim 42
Dependent Claim 22 words
The package of claim 37 wherein said package includes on some surfaces apertures sufficiently small to at least partially restrict microwave penetration.
Claim 43
Independent Claim 216 words
A method of microwave heating products which simultaneously heats the internal portions of said product and selectively raises to a higher temperature pre-selected areas of said products, said method comprising: locating a lossy chemical susceptor in a microwave environment, said chemical susceptor comprising a solute and a polar solvent for said solute, the amount of said solute being as a minimum an amount sufficient to provide a saturated solution of said solute in said polar solvent, and an amount which will depress the vapor pressure of said solvent at least 25% when compared to the vapor pressure of said solvent at its boiling point at standard pressure, placing said product which is to be treated in heat transfer association with at least a portion of said chemical susceptor and exposing said chemical susceptor to microwave radiation to heat said chemical susceptor, said chemical susceptor being heated to a higher temperature than said product, and a higher temperature than the fusion point of said solute portion of the chemical susceptor resulting in said solute portion changing to a liquid phase, and thereafter said solute portion continuing to heat in a steady state as long as said solute portion remains in said liquid phase and is exposed to sufficient microwave radiation energy to remain in said liquid phase.
Claim 44
Independent Claim 216 words
A method of microwave heating products which simultaneously heats the internal portions of said product and selectively raises to a higher temperature pre-selected areas of said products, said method comprising: locating a lossy chemical susceptor in a microwave environment, said chemical susceptor comprising a solute and a polar solvent for said solute, the amount of said solute being as a minimum an amount sufficient to provide a saturated solution of said solute in said polar solvent, and an amount which will depress the vapor pressure of said solvent at least 25% when compared to the vapor pressure of said solvent at its boiling point at standard pressure, placing said product which is to be treated in heat transfer association with at least a portion of said chemical susceptor and exposing said chemical susceptor to microwave radiation to heat said chemical susceptor, said chemical susceptor being heated to a higher temperature than said product, and a higher temperature than the fusion point of said solute portion of the chemical susceptor resulting in said solute portion changing to a liquid phase, and thereafter said solute portion continuing to heat in a steady state as long as said solute portion remains in said liquid phase and is exposed to sufficient microwave radiation energy to remain in said liquid phase.
Claim 45
Dependent Claim 115 words
A disposable microwave package comprising: a container of substantially non-lossy material for holding of a food product to be treated with microwave radiation energy, a chemical susceptor for microwave energy associated with said container for thermal contact with at least one surface of a product which is to be placed in said container, said chemical comprising an inorganic salt selected from the group consisting of Group IA and Group IIA salts, and a polar solvent for said salt, a low lossy substantially microwave transparent holder surface for said susceptor, a food product within said package, said food product having a low moisture content and a low density in order to change its heat load characteristics.
Claim 46
Dependent Claim 115 words
A disposable microwave package comprising: a container of substantially non-lossy material for holding of a food product to be treated with microwave radiation energy, a chemical susceptor for microwave energy associated with said container for thermal contact with at least one surface of a product which is to be placed in said container, said chemical comprising an inorganic salt selected from the group consisting of Group IA and Group IIA salts, and a polar solvent for said salt, a low lossy substantially microwave transparent holder surface for said susceptor, a food product within said package, said food product having a low moisture content and a low density in order to change its heat load characteristics.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-08-10 1985-02-09 1985-08-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-08-10 1989-02-09 1989-08-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-08-10 1993-02-09 1993-08-11 $7700.00 Window Closed / Lapsed

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