Materials with enhanced protection of light sensitive entities
View Patent ↗The present invention is based on a surprising discovery of new packaging materials used to package substances, such as foods, preventing the photo-oxidation of entities found in these substances. Specifically, these new packaging materials include a mixture of polymer resins having novel and specific ratios of filler, preferably calcium carbonate, and titanium dioxide resulting in the material having unexpected properties.
1. A composition comprising:
a) a melt processable resin;
b) titanium dioxide particles; and
c) CaCO 3 filler,
wherein the composition comprises a weight ratio of the CaCO 3 filler to the titanium dioxide particles selected from the group consisting of 17:1, 8.5:1, and 4.2:1.
2. The composition of claim 1 wherein the composition has an LPF value of greater than 60.
3. The composition of claim 1 wherein the melt processable resin is selected from the group consisting of polyethylene, polypropylene, polystyrene, polyvinylchloride, polymethylacrylate, acrylonitrile butadiene styrene, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyphenylene sulfide, polyacetal and or blends thereof.
4. The composition of claim 3 , wherein the melt processable resin is polyethylene.
5. The composition of claim 4 , wherein the polyethylene is a low density polyethylene.
6. The composition of claim 2 , wherein TiO 2 particles have a mean size distribution of less than or equal to about 350 nm.
7. The composition of claim 6 , wherein the TiO 2 particles have a mean size distribution of less than or equal to 250 nm.
8. The composition of claim 2 wherein the filler material has a particle size range between 20 and 1000 microns.
9. The composition of claim 1 wherein the composition is in the form of a package.
10. The composition of claim 1 wherein the package comprises a milk carton.
11. The composition of claim 10 wherein the milk carton has a wall thickness of between about 0.010 and 0.040 inch.
12. The composition of claim 11 wherein the milk carton has a wall thickness of between about 0.020 and 0.040 inch.
13. The composition of claim 1 wherein the TiO 2 particles have a mean size distribution of less than or equal to about 350 nm.
14. The composition of claim 13 wherein the TiO 2 particles have a mean size distribution of less than or equal to about 250 nm.
15. The composition of claim 1 wherein the CaCO 3 filler material has a particle size range between about 20 and 1000 microns.