In-situ polymerized polymer-platinum group metal nanoparticle blends and oxygen scavenging containers made therefrom
View Patent ↗A method of making a polymer composition comprising dispersed nanoparticles of an oxygen scavenging catalyst includes polymerizing one or more monomers or pre-polymers in the presence of a platinum group metal catalyst or precursor to obtain a polymer composition having dispersed nanoparticles of the platinum group metal. The oxygen scavenging catalyst is added during the polymerization as a solution of the platinum group metal or a compound thereof and a polyhydric alcohol (e.g., glycols). The food or beverage containers made from such polymer compositions exhibit high clarity and high oxygen scavenging properties.
1. A method of making a polymer composition comprising dispersed nanoparticles, the method comprising:
polymerizing one or more monomers or pre-polymers in the presence of a catalyst or catalyst precursor comprising a platinum group metal to obtain a polymer composition comprising dispersed nanoparticles of the platinum group metal,
wherein the catalyst or catalyst precursor is added before or during the polymerization as a solution comprising the platinum group metal or a compound thereof and a polyhydric alcohol.
2. The method of claim 1 , wherein the polymer composition comprises a polyester.
3. The method of claim 1 , wherein the polymer composition comprises polyethylene terephthalate (PET).
4. The method of claim 1 , wherein the platinum group metal comprises palladium.
5. The method of claim 1 , wherein the catalyst or catalyst precursor comprises a platinum group metal compound comprising a carboxylate, a sulfonate, or a phosphanate.
6. The method of claim 1 , wherein the dispersed nanoparticles of the platinum group metal is an oxygen scavenging catalyst.
7. The method of claim 1 , wherein the polyhydric alcohol comprises a glycol.
8. The method of claim 1 , wherein the polyhydric alcohol is ethylene glycol.
9. The method of claim 1 , wherein the polyhydric alcohol is selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, butane diol, terephthalic acid, and mixtures thereof.
10. The method of claim 1 , wherein the dispersed nanoparticles are present in an amount of 10 ppm or less.
11. The method of claim 1 , wherein the dispersed nanoparticles comprise an average diameter of 5 nm or less.
12. The method of claim 1 , wherein the polymer composition comprising the dispersed nanoparticles is substantially clear.
13. The method of claim 1 , wherein the catalyst or catalyst precursor is not melt blended with the polymer composition.
14. The method of claim 1 , wherein the catalyst or catalyst precursor comprises a platinum group metal compound comprising an acetate.
15. The method of claim 14 , wherein the platinum group metal compound is palladium acetate.
16. The method of claim 1 further comprising forming a wall for a package or container from the polymer composition.
17. The method of claim 16 , wherein the wall is formed by injection molding or stretch blow molding.
18. A food or beverage container comprising:
a wall comprising the polymer composition having dispersed nanoparticles obtained from the method of claim 1 ; and
a closure comprising a hydrogen generating material.
19. The food or beverage container of claim 18 , wherein the hydrogen generating material comprises sodium borohydride.
20. A method of making a polyethylene terephthalate composition comprising dispersed nanoparticles of an oxygen scavenging catalyst, the method comprising:
adding a glycol solution comprising a palladium compound before or during polymerization of polyethylene terephthalate to form a polyethylene terephthalate composition comprising dispersed nanoparticles of palladium.