Microwave heater compositions for use in microwave ovens

• US 5,118,747 A
• Filed: 06/11/1990
• Issued: 06/02/1992
• Est. Priority Date: 09/01/1988
• Status: Expired due to Term

• Current Assignee: Graphic Packaging International LLC (Graphic Packaging International Incorporated)
• Original Assignee: James River Corporation of Virginia (KOCH Industries Incorporated)
• Inventors: Lafferty, Terrence P., Pollart, Kenneth A.
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): Brown, Christopher
• Application Number:
  US07/536,212
• Time in Patent Office: 722 Days
• Field of Search: 524/425, 524/439, 524/441, 524/445, 524/495, 524/496, 524/424, 524/435, 524/437, 524/440, 524/444, 524/543, 252/503, 252/506, 252/508, 252/510, 252/511, 252/512, 252/513, 252/572, 426/107, 426/241, 426/243, 219/10.55 E
• US Class Current: 524/424
• CPC Class Codes: B65D 2581/3447 Heat attenuators, blocking agents or heat insulators for temperature control
• CPC Class Codes: B65D 2581/3448 Binders for microwave reactive materials, e.g. for inks or coatings
• CPC Class Codes: B65D 2581/3464 Microwave reactive material applied by ink printing
• CPC Class Codes: B65D 2581/3472 Aluminium or compounds thereof
• CPC Class Codes: B65D 2581/3479 Other metallic compounds, e.g. silver, gold, copper, nickel
• CPC Class Codes: B65D 2581/3483 Carbon, carbon black, or graphite
• CPC Class Codes: B65D 81/3446 specially adapted to be heated by microwaves
• CPC Class Codes: C09D 5/38 Paints containing free metal not provided for above in groups C09D5/00 - C09D5/36
• CPC Class Codes: H01C 7/027 consisting of conducting or semi-conducting material dispersed in a non-conductive organic material

Abstract

Microwave interactive coating compositions are disclosed which comprise finely divided carbon, a powdered inert solid and a binder. A preferred composition comprises finely divided carbon, finely divided microwave reactive metal, powdered inert material and a dielectric binder, preferably an acrylic latex. These compositions are capable of producing microwave reactive heaters comparable to those produced by vapor deposition of metals on a carrier film.

Claims

1. A microwave interactive coating composition consisting essentially of finely divided carbon, a finely divided microwave reactive metal selected from the group consisting of aluminum, tin, bronze and nickel, a powdered inert solid material selected from the group consisting of alumina hydrate, silica, titanium oxides, aluminosilicates, clay, and calcium carbonate, and an acrylic latex binder dispersed in an aqueous carrier wherein the weight ratio of metal to carbon in the composition is in the range of from about 0.2 to about 2 parts metal per part carbon, the powdered inert solids comprise 10 to 35 weight percent of the total solids in the composition and the binder solids comprise 30 to 40 weight percent of the total solids.

2. A microwave interactive coating composition as defined in claim 1 wherein the finely divided carbon is graphite.

3. A microwave interactive coating composition as defined in claim 1 wherein the finely divided carbon is carbon black.

4. A microwave interactive coating composition as defined in claim 1 wherein the metal is aluminum flake.

5. A microwave interactive coating composition consisting of finely divided carbon, aluminum flake, clay, and an acrylic latex binder dispersed in an aqueous carrier wherein the weight ratio of aluminum to carbon in the composition is in the range of from about 0.2 to about 2 parts aluminum per part carbon, the powdered inert solids comprise 10 to 35 weight percent of the total solids in the composition and the binder solids comprise 30 to 40 weight percent of the total solids.