Selectively microwave-permeable membrane susceptor systems

Claim 2

A microwave susceptor for use in food packaging, the susceptor comprising: a) at least one substantially microwave-transparent substrate, the substrate having opposed surfaces; b) at least one microwave-absorptive coating disposed as a pattern upon at least one of said opposed surfaces, said microwave-absorptive coating constructed and arranged to absorb microwave energy and generate heat; and c) at least one microwave-reflective coating disposed as a pattern proximate to at least one of said opposed surfaces, said microwave-reflective coating constructed and arranged to reflect microwave energy, to thereby reduce the amount of such microwave energy that reaches the microwave-absorptive coating when the susceptor is exposed to a microwave energy field.

Claim 3

A microwave susceptor as in claim 1 comprising at least one substrate with one microwave-absorptive coating and one microwave-reflective coating disposed on opposing surfaces thereof.

Claim 4

A microwave susceptor as in claim 1 wherein at least one of said microwave absorptive coating and said microwave reflective coating is a vapor deposited coating.

Claim 5

A microwave susceptor as in claim 3, wherein at least one of said microwave reflective coating is disposed in a pinwheel pattern.

Claim 6

A microwave susceptor as in claim 3 wherein at least one of said microwave absorptive coating and microwave reflective coating is a vapor deposited coating.

Claim 7

A microwave susceptor as in claim 5 wherein the substrate comprises a polymeric film.

Claim 8

A microwave susceptor as in claim 1 wherein said microwave reflective coatings that are disposed proximate to at least one of said opposed surfaces of the substrate are in phased array.

Claim 9

A microwave susceptor as in claim 1 wherein the substrate comprises a paper or paper laminate.

Claim 10

A susceptor as in claim 1 wherein the substrate comprises a cellulosic material.

Claim 11

A microwave susceptor as in claim 1 wherein the microwave absorptive coating has a resistivity of between about 30 and about 500 ohms per square.

Claim 12

A microwave susceptor as in claim 1 wherein the microwave-reflective coating has a resistivity of between about 10 and about 150 ohms per square.

Claim 13

A microwave susceptor as in claim 11 wherein the microwave-absorptive coating comprises elemental aluminum.

Claim 14

A microwave susceptor as in claim 12 wherein the microwave reflective coating comprises a metal or metallic alloy having a bulk resistivity higher than that of elemental aluminum.

Claim 15

A microwave susceptor as in claim 13 wherein, the microwave reflective coating includes a plurality of regions having differing reflectivities.

Claim 16

A microwave susceptor as in claim 13 wherein the microwave absorptive coating includes a plurality of regions having differing microwave energy absorption characteristics.

Claim 17

A microwave susceptor as in claim 1 wherein the microwave absorptive coating comprises a metal or metallic alloy.

Claim 18

A microwave susceptor as in claim 1 wherein the microwave reflective coating comprises a metal or metallic alloy.

Claim 19

A microwave susceptor as in claim 1 adapted to undergo nonuniform heating in the presence of a uniform microwave energy field.

Claim 20

A microwave susceptor as in claim 18 wherein the regions having differing reflectivities comprise microwave reflective coatings comprising differing materials.

Claim 21

A microwave susceptor as in claim 18 wherein the difference patterning geometries of said microwave reflective coatings are in phased array.

Claim 22

A microwave susceptor as in claim 18 wherein the regions having differing reflectivities comprise microwave-reflective coatings having differing patterning geometries.

Claim 23

A microwave susceptor as in claim 19 wherein the regions having differing microwave absorption characteristics comprise microwave absorptive coatings comprising differing materials.

Claim 24

A microwave susceptor as in claim 19 wherein the regions having differing microwave absorption characteristics comprise microwave absorptive coatings having differing patterning geometries.

Claim 25

A microwave susceptor as in claim 1 having microwave absorptive coatings disposed on opposing surfaces of the substrate.

Claim 26

A microwave susceptor as in claim 24 having microwave reflective coatings disposed upon each of the microwave absorptive coatings.

Claim 27

A microwave susceptor as in claim 1 having microwave reflective coatings disposed on opposing surfaces of the substrate.

Claim 28

A microwave susceptor as in claim 25 wherein the microwave reflective coating disposed on opposing surfaces of the substrate are in phased array.

Claim 29

A microwave susceptor as in claim 26 wherein the substrate comprises a polyester film.

Claim 30

A microwave susceptor as in claim 26 wherein the substrate comprises a paper or paper laminate.

Claim 31

A microwave susceptor as in claim 1 comprising a substrate and a microwave reflective coating disposed thereon, the coating being at least partially removed in a pattern to provide microwave absorptive characteristics in regions where the coating has been removed.

Claim 32

A microwave susceptor as in claim 28 wherein the substrate comprises a cellulosic material.

Claim 33

A microwave susceptor as in claim 1 comprising at least two substrates that are made of different materials.

Claim 34

A package structure for microwave cooking of food, comprising: a receptacle for holding of food to be cooked; a microwave susceptor affixed to at least a portion of the receptable, said susceptor optionally in contact with the food, the susceptor comprising; a) at least one substantially microwave-transparent substrate, the substrate having opposed surfaces; b) at least one microwave-absorptive coating disposed upon at least one of said opposed surfaces, said microwave-absorptive coating constructed and arranged to absorb microwave energy and generate heat; and c) at least one microwave-reflective coating disposed as a pattern proximate to at least one of said opposed surfaces to thereby reduce the amount of such microwave energy that reaches the microwave-absorptive coating when the susceptor is exposed to a microwave energy field, said microwave-reflective coating constructed and arranged to reflect microwave radiation.

Claim 35

A package structure for microwave cooking of food, comprising: a receptacle for holding of food to be cooked; a microwave susceptor affixed to at least a portion of the receptable, said susceptor optionally in contact with the food, the susceptor comprising; a) at least one substantially microwave-transparent substrate, the substrate having opposed surfaces; b) at least one microwave-absorptive coating disposed upon at least one of said opposed surfaces, said microwave-absorptive coating constructed and arranged to absorb microwave energy and generate heat; and c) at least one microwave-reflective coating disposed as a pattern proximate to at least one of said opposed surfaces to thereby reduce the amount of such microwave energy that reaches the microwave-absorptive coating when the susceptor is exposed to a microwave energy field, said microwave-reflective coating constructed and arranged to reflect microwave radiation.

Claim 36

A package structure as in claim 33, comprising at least one substrate with one microwave-absorptive coating and one microwave-reflective coating disposed on opposing surfaces thereof.

Claim 37

A package structure as in claim 34, wherein at least one of the microwave-absorptive coating and microwave reflective coating comprises a patterned surface.

Claim 38

A package structure of claim 33, wherein said microwave-reflective coatings that are disposed proximate to at least one of said opposed surfaces of the substrate are in phased array.

Claim 39

A package structure of claim 33, comprising at least two substrates that are made of different materials.

Claim 40

A microwave susceptor as in claim 33, wherein the microwave reflective coatings disposed proximate to at least one of said opposing surfaces of the substrate are disposed in a pinwheel pattern.

Claim 41

A package structure as in claim 35, wherein said microwave reflective coating is disposed in a pinwheel pattern.

Claim 42

A microwave susceptor as in claim 1, wherein said at least one microwave-absorptive coating and said at least one microwave-reflective coating each have a resistivity, said microwave-absorptive coating having a higher resistivity than the resistivity of the microwave-reflective coating.

Claim 43

A package structure as in claim 33, wherein said at least one microwave-absorptive coating and said at least one microwave-reflective coating each have a resistivity, said microwave-absorptive coating having a higher resistivity than the resistivity of the microwave-reflective coating.

Claim 44

A microwave susceptor for use in food packaging, the susceptor comprising: (a) at least one substantially microwave-transparent substrate, the substrate having opposed surfaces; (b) at least one microwave-absorptive coating disposed as a pattern upon at least one of said opposed surfaces; and (c) at least one microwave-reflective coating disposed as a plurality of separate reflective regions separated by nonreflective regions, the coating proximate to at least one of said opposed surfaces, said microwave reflective coating constructed and arranged to reflect an amount of microwave radiation sufficient to prevent heating of the microwave-absorptive coating to a level which leads to deformation and volatilization of the microwave-transparent substrate.

Claim 45

A microwave susceptor for use in food packaging, the susceptor comprising: (a) at least one substantially microwave-transparent substrate, the substrate having opposed surfaces; (b) at least one microwave-absorptive coating disposed as a pattern upon at least one of said opposed surfaces; and (c) at least one microwave-reflective coating disposed as a plurality of separate reflective regions separated by nonreflective regions, the coating proximate to at least one of said opposed surfaces, said microwave reflective coating constructed and arranged to reflect an amount of microwave radiation sufficient to prevent heating of the microwave-absorptive coating to a level which leads to deformation and volatilization of the microwave-transparent substrate.

Claim 46

The microwave susceptor of claim 42 in which the microwave absorptive coating has a resistivity of between about 30 and about 500 ohms per square.

Claim 47

The microwave susceptor of claim 43, wherein the microwave reflective coating has a resistivity less than the resistivity of the microwave-absorptive coating.