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EP-4735253-A1 - MULTILAYER POLYETHYLENE FILMS WITH A THIN LAYER LOADED WITH A MINERAL AND ETHYLENE COPOLYMER

EP4735253A1EP 4735253 A1EP4735253 A1EP 4735253A1EP-4735253-A1

Abstract

A multilayer film includes a first outer layer, a second outer layer, and at least one inner layer positioned between the first outer layer and the second outer layer. The at least one inner layer includes: greater than or equal to 5 wt.% CaCO 3 based on a total weight of the inner layer; greater than or equal to 5 wt.% of an ethylene copolymer selected from the group consisting of ethylene/butyl acrylate copolymer, ethylene/ethyl acrylate copolymer, ethylene/methyl acrylate copolymer, and ethylene/vinyl acetate copolymer based on the total weight of the inner layer; and greater than or equal to 25 wt.% of a combination of the CaCO 3 and the ethylene copolymer based on the total weight of the inner layer. The inner layer is greater than or equal to 2% and less than or equal to 40% of the total thickness of the multilayer film

Inventors

  • MAKSIMOVIC, Ksenija
  • NIETO PALOMO, Jesús

Assignees

  • Dow Global Technologies LLC

Dates

Publication Date
20260506
Application Date
20240625

Claims (15)

  1. 1. A multilayer film comprising: a first outer layer; a second outer layer; at least one inner layer positioned between the first outer layer and the second outer layer, wherein the at least one inner layer comprises: greater than or equal to 5 wt.% CaCOs based on a total weight of the at least one inner layer; greater than or equal to 5 wt.% of an ethylene copolymer selected from the group consisting of ethylene/butyl acrylate copolymer, ethylene/ethyl acrylate copolymer, ethylene/methyl acrylate copolymer, and ethylene/vinyl acetate copolymer based on the total weight of the at least one inner layer; greater than or equal to 25 wt.% of a combination of the CaC'Os and the ethylene copolymer based on the total weight of the at least one inner layer; and greater than or equal to 2% and less than or equal to 40% of a total thickness of the multilayer fdm.
  2. 2. The multilayer fdm of claim 1, wherein the at least one inner layer comprises greater than or equal to 40 wt.% of a combination of the CaCOs and the ethylene copolymer based on the total weight of the at least one inner layer.
  3. 3. The multilayer fdm of any of the preceding claims, wherein the at least one inner layer comprises greater than or equal to 15 wt.% of CaC'Os based on the total weight of the at least one inner layer.
  4. 4. The multilayer film of any of the preceding claims, wherein the at least one inner layer comprises greater than or equal to 15 wt.% of the ethylene copolymer based on the total weight of the at least one inner layer.
  5. 5. The multilayer fdm of any of the preceding claims, wherein an amount of CaC'Os and ethylene copolymer in the at least one inner layer satisfies the following inequality: 1280 where y is an amount of ethylene copolymer in wt.% and x is an amount of CaCC in wt.% based on the total weight of the at least one inner layer.
  6. 6. The multilayer fdm of any of the preceding claims, wherein an amount of CaCOs and ethylene copolymer in the at least one inner layer satisfies the following inequality: where y is an amount of ethylene copolymer in wt.% and x is an amount of CaCC in wt.% based on the total weight of the at least one inner layer.
  7. 7. The multilayer film of any of the preceding claims, wherein the at least one inner layer further comprises an ethylene-based polymer.
  8. 8. The multilayer film of claim 7, wherein the at least one inner layer comprises the ethylene-based polymer in an amount that is less than or equal to 75 wt.% based on the total weight of the at least one inner layer.
  9. 9. The multilayer film of any of the preceding claims, wherein the multilayer film has greater than or equal to 12% and less than or equal to 400% improvement in Elmendorf Tear in a cross-direction compared to a multilayer film having equivalent outer layer compositions and thickness but does not comprise the CaCOs and the ethylene copolymer in an inner layer.
  10. 10. The multilayer film of any of the preceding claims, wherein the multilayer film has greater than or equal to 13% and less than or equal to 400% improvement in Elmendorf Tear in a machine-direction compared to a multilayer film having equivalent outer layer compositions and thickness but does not comprise the CaCOs and the ethylene copolymer in an inner layer.
  11. 11. The multilayer film of any of the preceding claims, wherein the multilayer film has a thickness that is greater than or equal to 25 microns and less than or equal to 100 microns.
  12. 12. The multilayer film of any of the preceding claims, wherein the at least one inner layer comprises greater than or equal to 5% and less than or equal to 30% of the thickness of the multilayer film.
  13. 13. The multilayer film of any of the preceding claims, wherein the at least one inner layer comprises greater than or equal to 5% and less than or equal to 10% of the thickness of the multilayer film.
  14. 14. The multilayer film of any of the preceding claims, wherein at least one of the first outer layer and the second outer layer comprises TTDPE, TDPE, ULDPE, VLDPE, MDPE, HDPE, and combinations thereof.
  15. 15. The multilayer film of any of the preceding claims, wherein the first outer layer and the second outer layer comprise greater than or equal to 60% and less than or equal to 98% of a total thickness of the multilayer film.

Description

MULTILAYER POLYETHYLENE FILMS WITH A THIN LAYER LOADED WITH A MINERAL AND ETHYLENE COPOLYMER CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of Spanish Patent Application No. P202330543 filed June 28, 2023, the contents of which are incorporated in their entirety herein. TECHNICAL FIELD [0002] Embodiments of the present disclosure generally relate to multilayer films, and more particularly relate to multilayer films including a thin layer comprising a mineral and ethylenebased copolymers. INTRODUCTION [0003] Multilayer films that incorporate ethylene-based polymers, are widely used in industrial and consumer products. Such films used in industrial and consumer products often require desirable properties such as sufficient tear resistance — for example, to avoid the film from breakage during use. The combination of layers and materials can allow for good performance of the films, but there is a continued need to produce ever stronger multilayer films as well as thinner films and/or films that use less ethylene-based polymers. SUMMARY [0004] Embodiments of the present disclosure meet one or more of the foregoing needs by providing multilayer films that exhibit desirable tear resistance and include recycle-compatible ethylene-based polymers. Higher mechanical resistance makes films more suitable for packaging applications by providing less environmental impact, higher consumer convenience, and less food waste — in the case of food packaging. However, multilayer films comprised of ethylene-based films often have lower mechanical resistance than multilayer films comprising other polymers, such as propylene, amide, and terephthalate. [0005] The multilayer films of embodiments disclosed and described herein have improved tear resistance compared to similar multilayer films. Moreover, multilayer films according to one or more embodiments are thin multilayer films that have the same or similar tear resistance compared to thicker films. In addition, multilayer films according to embodiments use less ethylene-based polymers and are less costly to make than fdms with comparable, or lesser, tear resistance. The multilayer fdms according to embodiments disclosed herein comprise at least a first outer layer, second outer layer, and an inner layer, wherein the inner layer comprises a mineral and an ethylene-based copolymer and is less than 40% of the total thickness of the multilayer film. Without being bound by theory, among the other features, the structure of the film with a thin inner layer and a specific combination of a mineral and ethylene-based copolymer results in surprisingly desirable tear resistance and maintained or improved dart impact when compared to existing film structures. [0006] Disclosed herein are multilayer films. In one aspect, a multilayer film comprises: a first outer layer; a second outer layer; at least one inner layer positioned between the first outer layer and the second outer layer, wherein the at least one inner layer comprises: greater than or equal to 5 wt.% CaCOs based on a total weight of the at least one inner layer; greater than or equal to 5 wt.% of an ethylene copolymer selected from the group consisting of ethylene/butyl acrylate copolymer, ethylene/ethyl acrylate copolymer, ethylene/methyl acrylate copolymer, and ethylene/vinyl acetate copolymer based on the total weight of the at least one inner layer; greater than or equal to 25 wt.% of a combination of the CaCC and the ethylene copolymer based on the total weight of the at least one inner layer; and greater than or equal to 2% and less than or equal to 40% of the total thickness of the multilayer fdm. [0007] These and other embodiments are described in more detail in the Detailed Description. BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIG. 1 is a scatter plot showing Elmendorf tear in the machine direction based on the amounts of ethylene copolymer and calcium carbonate (CaCCb) in an inner layer according to embodiments disclosed and described herein; [0009] FIG. 2 is a scatter plot showing Elmendorf tear in the cross direction based on the amounts of ethylene copolymer and CaCOs in an inner layer according to embodiments disclosed and described herein; [0010] FIG. 3 is a scatter plot showing puncture energy based on the amounts of ethylene copolymer and CaCOs in an inner layer according to embodiments disclosed and described herein; [0011] FIG. 4 is a scater plot showing dart impact based on the amounts of ethylene copolymer and CaCC in an inner layer according to embodiments disclosed and described herein; [0012] FIG. 5 is a bar graph showing Elmendorf tear in the machine direction for comparative samples 7-9 and samples 12 and 13 of films according to the examples provided herein; [0013] FIG. 6 is a bar graph showing Elmendorf tear in the cross direction for comparative samples 7-9 and samples 12 and 13 of films according to the examples provided herein; [0014] FIG. 7 is a bar graph showi