Multilayer films and related uses thereof

Patent metadata

Field	Value
Publication number	US-10927431-B2
Application number	US-201515540225-A
Country	US
Kind code	B2
Filing date	Dec 15, 2015
Priority date	Dec 31, 2014
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

Embodiments disclosed herein include multilayer films that have at least two layers. More particularly, disclosed in embodiments herein are multilayer films that include at least a first layer and a second layer, wherein the first layer includes at least one polyethylene polymer, wherein the second layer includes at least one water-soluble polymer, wherein the second layer is insoluble in water at a temperature of less than 20° C., wherein the second layer is soluble in water at a temperature of 20° C. or greater, and wherein the first layer has one or more openings through the first layer to expose the second layer. Also disclosed herein are methods of using such multilayer films for extracting metal from metal ore.

First claim

What is claimed is:

1. A multilayer film comprising at least a first layer, a second layer, and a third layer, wherein the first layer comprises at least one polyethylene polymer, wherein the second layer comprises at least one water-soluble polymer, wherein the second layer is insoluble in water at a temperature of less than 20° C., wherein the second layer is soluble in water at a temperature of 20° C. or greater, and wherein the first layer has one or more openings through the first layer to expose the second layer, wherein the second layer is between the first layer and the third layer, wherein the third layer comprises at least one polyethylene polymer and has one or more openings through the third layer to expose the second layer, and wherein at least one of the openings in the first layer at least partially overlaps with at least one of the openings in the third layer.

2. The multilayer film according to claim 1 , wherein the at least one polyethylene polymer comprises at least one copolymer of ethylene and at least one comonomer selected from the group consisting of C 3 -C 20 α-olefins, wherein the copolymer of ethylene has a density in the range 0.900 to 0.960 grams/cm 3 and a Melt Index I 2.16 in the range of 0.1 to 4.0 decigrams/minute, wherein Melt Index I 2.16 is measured in accordance with ASTM D-1238 (condition 190° C. with a 2.16 kg load) and density is measured in accordance with ASTM D-792.

3. The multilayer film according to claim 2 , wherein the at least one copolymer has a I 10 /I 2.16 value in the range from 5 to 10, wherein I 2.16 is measured in accordance with ASTM D-1238 (condition 190° C. with a 2.16 kg load) and I 10 is measured in accordance with ASTM D-1238 (condition 190° C. with a 10 kg load).

4. The multilayer film according to claim 1 , wherein the first layer has a thickness in the range from 20 to 400 micrometers, the second layer has a thickness in the range from 10 to 300 micrometers, and the third layer has a thickness in the range from 20 to 400 micrometers.

5. The multilayer film according to claim 1 , wherein the at least one water soluble polymer is selected from the group consisting of polyvinyl alcohol, poly-acryl amide, and blends thereof.

6. The multilayer film according to claim 1 , wherein the first layer and third layer each have a property selected from the group consisting of: a Dart Drop Impact value in the range from 50 to 1500 grams and measured in accordance with ASTM 1709, a Puncture Resistance value in the range from 0.1 to 15 Joules/cm 3 and measured in accordance with ASTM 5748, an Energy to Break value in the range from 0.01 to 15 Joules and measured in accordance with ASTM 5748, an Elmendorf Tear Strength MD value in the range from 10 to 5000 grams and measured in accordance with ASTM D1922, an Elmendorf Tear Strength CD value in the range from 10 to 5000 grams and measured in accordance with ASTM D1922, and combinations thereof.

7. The multilayer film according to claim 1 , wherein the second layer has a property selected from the group consisting of: a Dart Drop Impact value in the range from 200 to 1500 grams and measured in accordance with ASTM 1709, a Puncture Resistance value in the range from 0.5 to 20 Joules/cm 3 and measured in accordance with ASTM 5748, an Energy to Break value in the range from 0.01 to 15 Joules and measured in accordance with ASTM 5748, an Elmendorf Tear Strength MD value in the range from 100 to 1500 grams and measured in accordance with ASTM D1922, an Elmendorf Tear Strength CD value in the range from 100 to 1500 grams and measured in accordance with ASTM D1922, and combinations thereof.

8. The multilayer film according to claim 1 , wherein the first layer has a plurality of openings and each opening has an opening area in the range from 0.1 to 10 cm 2 and wherein the third layer has a plurality of openings an each opening has an opening area in the range from 0.1 to 10 cm 2 .

9. The multilayer film according to claim 8 , wherein the distance between the centers of adjacent openings in the first layer is in the range from 2 to 10 cm and the distance between the centers of adjacent openings in the third layer is in the range from 2 to 10 cm.

10. The multilayer film according to claim 8 , wherein at least a portion of the first layer has an opening density in the range from 0.01 to 2 opening s/cm 2 and at least a portion of the third layer has an opening density in the range from 0.01 to 2 opening s/cm 2 .

11. A method of extracting metal from metal ore, the method comprising:
providing a barrier membrane;
positioning a first volume of metal ore over the barrier membrane;
positioning a multilayer film over the first volume of metal ore, wherein the multilayer film comprises at least a first layer, a second layer, and a third layer, wherein the first layer comprises at least one polyethylene polymer, wherein the second layer comprises at least one water-soluble polymer, wherein the second layer is insoluble in water at a temperature of less than 20° C., wherein the second layer is soluble in water at a temperature of 20° C. or greater, and wherein the first layer has one or more openings through the first layer to expose the second layer, wherein the second layer is between the first layer and the third layer, wherein the third layer comprises at least one polyethylene polymer and has one or more openings through the third layer to expose the second layer, and wherein at least one of the openings in the first layer at least partially overlaps with at least one of the openings in the third layer;
positioning a second volume of metal ore over the multilayer film over; and
dispensing a metal extraction solution onto the second volume of metal ore so that the metal extraction can contact at least a portion of the second volume of metal ore to extract metal from the metal ore, wherein at least a portion of the solution flows through the second volume of metal ore and is in fluid communication with the drain system.

12. The method according to claim 11 , further comprising, after dispensing the metal extraction solution, dispensing an aqueous liquid having a temperature of 20° C. or greater so that at least a portion of the second layer dissolves and permits the aqueous solution to flow through the multilayer film via the one or more openings in the first layer.

Assignees

• Dow Quim De Colombia S A
• Pbb Polisur Srl
• Dow Global Technologies Llc

Inventors

• Zanetti Maximiliano
• Niampira Miguel Molano
• Gomes Jorge C

Classifications

• Y02P10/20

  Recycling · CPC title

• B32B2307/54

  Yield strength; Tensile strength · CPC title

• B32B2307/7166

  Water-soluble, water-dispersible · CPC title

• B32B2307/542

  Shear strength · CPC title

• B32B3/266

  characterised by an apertured layer, the apertures going through the whole thickness of the layer, e.g. expanded metal, perforated layer, slit layer regular cells B32B3/12 · CPC title