Water activated oxygen scavenging composition
View Patent ↗An efficient oxygen scavenging composition for use in film forming polymers is disclosed wherein the oxygen scavenging composition comprises an oxidizable metal particle, such as elemental iron; a water hydrolysable Lewis acid, such as aluminum chloride; and an acidifying electrolyte such as sodium or potassium bisulfate.
1. An oxygen-scavenging composition wherein said oxygen scavenging composition comprises oxidizable elemental metal particles in their 0 valence state, at least one water hydrolysable Lewis acid salt and/or its adducts, and at least one acidifying electrolyte, wherein the acidifying electrolyte comprises at least one solid compound that produces a pH less than 7 in a dilute aqueous solution and substantially disassociates into positive and negative ions in the presence of moisture.
2. The oxygen-scavenging composition of claim 1 wherein the oxidizable metal comprises iron.
3. The oxygen-scavenging composition of claim 1 , wherein the water hydrolysable Lewis acid salt is selected from the group consisting of AlCl 3 , AlBr 3 , FeCl 2 , FeCl 3 and FeBr 2 .
4. The oxygen-scavenging composition of claim 1 , wherein the water hydrolysable Lewis acid salt is AllCl 3 .
5. The oxygen-scavenging composition of claim 1 , wherein the acidifying electrolyte is selected from the group consisting of sulfamic acid, zinc sulfate, ferrous sulfate and sodium bisulfate.
6. The oxygen-scavenging composition of claim 5 , wherein the water hydrolysable Lewis acid salt is selected from the group consisting of AlCl 3 , AlBr 3 , FeCL 2 , FeCl 3 and FeBr 2 .
7. The oxygen-scavenging composition of claim 5 , wherein the water hydrolysable Lewis acid salt is AlCl 3 .
8. The oxygen-scavenging composition of claim 1 , wherein the acidifying electrolyte is selected from the group consisting of potassium bisulfate, ammonium bisulfate, ammonium sulfite, ammonium bisulfite, and sodium bisulfite.
9. The oxygen-scavenging composition of claim 8 , wherein the water hydrolysable Lewis acid salt is selected from the group consisting of AlCl 3 , AlBr 3 , FeCl 2 , FeCl 3 and FeBr 2 .
10. The oxygen-scavenging composition of claim 8 , wherein the water hydrolysable Lewis acid salt is AlCl 3 .
11. The oxygen-scavenging composition of claim 1 , wherein the water hydrolysable Lewis acid salt is FeBr 3 .
12. The oxygen-scavenging composition of claim 11 , wherein the acidifying electrolyte is selected from the group consisting of sulfamic acid, zinc sulfate, ferrous sulphate, sodium bisulfate, potassium bisulfate, ammonium bisulfate, ammonium sulfite, ammonium bisulfite, and sodium bisulfite.
13. The oxygen-scavenging composition of claim 11 , wherein the acidifying electrolyte is sodium bisulfate.