# US 5,332,590 A · Method of absorbing oxygen by employing a particulate annealed electrolytically reduced iron

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- Number: US 5,332,590 A
- Document ID: US5332590A
- Status: Granted
- Kind: A
- Application number: 08/097,291
- Filed: 1993-07-26
- Granted: 1994-07-26
- Earliest claimed: 1992-05-26
- Assignees: Multiform Desiccants, Inc.
- Inventors: George E. McKedy
- Web page: https://patentgrep.com/patent/US5332590A

## CPC

- C09K 15/02: containing inorganic compounds
- A23B 2/717: Oxygen absorbent
- B01J 20/0229: {Compounds of Fe}
- B01J 20/046: {containing halogens, e.g. halides}
- B01J 20/103: {comprising silica}
- B01J 20/28004: {Sorbent size or size distribution, e.g. particle size}
- B01J 20/2805: {Sorbents inside a permeable or porous casing, e.g. inside a container, bag or membrane}
- B01J 2220/42: Materials comprising a mixture of inorganic materials (materials coated or impregnated on a carrier B01J20/32)
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- A23B: PRESERVATION OF FOODS, FOODSTUFFS OR NON-ALCOHOLIC BEVERAGES; CHEMICAL RIPENING OF FRUIT OR VEGETABLES
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS

## Abstract

An oxygen-absorbing composition containing particulate annealed electrolytically reduced iron of between about 100 mesh and 325 mesh in an amount of about up to 99.6% by weight, a salt such as sodium chloride in an amount by weight of about up to 3.5%, and optionally a water-attracting and supplying component such as silica gel of a mesh size of between about 30 mesh and 325 mesh in an amount by weight of up to about 80%. A packet for absorbing oxygen including a stain and grease resistant envelope containing the oxygen-absorbing composition. A grease and stain resistant laminate consisting of plies of various plastics and grease and stain resisting paper.

## Claims

### Claim 1

A method of absorbing oxygen in a container containing a product which can be deleteriously affected by oxygen and which is subjected to temperatures below about 50.degree. F. for storage comprising the steps of placing said product into a container which is to be subjected to temperatures below 50.degree. F., adding an oxygen permeable envelope containing an oxygen-absorbing composition containing both particulate annealed electrolytically reduced iron and a salt to said container, and sealing said container containing said product and said oxygen-absorbing composition, said particulate annealed electrolytically reduced iron and said salt of said composition being present in said container in sufficient proportions for said salt to combine with moisture in said container to form an electrolyte which in turn activates said iron to absorb oxygen in said container.

### Claim 2 (depends on 1)

A method as set forth in claim 1 wherein said annealed electrolytically reduced iron is present in an amount of up to about 99.6% of the total weight of the composition.

### Claim 3 (depends on 2)

A method as set forth in claim 2 wherein said envelope further contains a water-attracting and supplying component.

### Claim 4 (depends on 3)

A method as set forth in claim 3 wherein said water-attracting and supplying component is present by weight in an amount of up to about 80% of the total weight of the composition.

### Claim 5 (depends on 4)

A method as set forth in claim 4 wherein said water-attracting and supplying component is present by weight in an amount of between about 40% and 50% of the total weight of the composition.