US-20260124818-A1 - LAMINATE WITH MACHINE DIRECTION ORIENTED MULTILAYER FILM

US20260124818A1US 20260124818 A1US20260124818 A1US 20260124818A1US-20260124818-A1

Abstract

The present disclosure provides a laminate. In an embodiment, the laminate comprises a first machine direction oriented (1MDO) multilayer film. The 1MDO multilayer film comprises (a) a skin layer comprising (i) a skin layer (SL) first ethylene/α-olefin copolymer having a density from 0.870 g/cc to 0.920 g/cc, and (ii) an optional skin layer (SL) second ethylene/α-olefin copolymer having a density from 0.900 g/cc to 0.980 g/cc. The 1MDO multilayer film comprises (b) a first intermediate layer in direct contact with the skin layer. The first intermediate layer comprises (i) a first intermediate layer (FIL) first ethylene/α-olefin copolymer having a density from 0.940 g/cc to 0.980 g/cc, and (ii) a first intermediate layer (FIL) second ethylene/a-olefin copolymer having density from 0.916 g/cc to 0.980 g/cc. The 1MDO multilayer film comprises (c) a core layer in direct contact with the first intermediate layer (b). The core layer (c) comprises (i) a core layer (CL) first ethylene/a-olefin copolymer having a density from 0.915 g/cc to 0.980 g/cc. The 1MDO multilayer film comprises (d) a second intermediate layer in direct contact with the core layer. The second intermediate layer comprises an ethylene-based polymer. The 1MD0 multilayer film comprises (e) an interior layer in direct contact with the second intermediate layer. The interior layer comprises an ethylene-based polymer. The laminate comprises a second machine direction oriented (2MDO) film and an adhesive layer between the 1MDO multilayer film and the 2MDO film.

Inventors

Prem K. Chaturvedi
Nrusingh Sahu
Nimisha Rahul Pathare
Martin Keith Hill

Assignees

DOW GLOBAL TECHNOLOGIES LLC

Dates

Publication Date: 20260507
Application Date: 20231018
Priority Date: 20221018

Claims (12)

1 . A laminate comprising: a first machine direction oriented (1MDO) multilayer film comprising (a) a skin layer comprising (i) a skin layer (SL) first ethylene/α-olefin copolymer having a density from 0.870 g/cc to 0.920 g/cc, and (ii) an optional skin layer (SL) second ethylene/α-olefin copolymer having a density from 0.900 g/cc to 0.980 g/cc; (b) a first intermediate layer in direct contact with the skin layer, the first intermediate layer comprising (i) a first intermediate layer (FIL) first ethylene/α-olefin copolymer having a density from 0.940 g/cc to 0.980 g/cc, and (ii) a first intermediate layer (FIL) second ethylene/α-olefin copolymer having density from 0.916 g/cc to 0.980 g/cc; (c) a core layer in direct contact with the first intermediate layer (b), the core layer (c) comprising (i) a core layer (CL) first ethylene/α-olefin copolymer having a density from 0.915 g/cc to 0.980 g/cc; (d) a second intermediate layer in direct contact with the core layer, the second intermediate layer comprising an ethylene-based polymer; (e) an interior layer in direct contact with the second intermediate layer, the interior layer comprising an ethylene-based polymer; a second machine direction oriented (2MDO) film; and an adhesive layer between the 1MDO multilayer film and the 2MDO film.
2 . The laminate of claim 1 wherein the skin layer (a) comprises (i) from 50 wt % to 80 wt % of the SL first ethylene/α-olefin copolymer having a density from 0.870 g/cc to 0.920 g/cc and a melt temperature from 55° C. to 125° C., and (ii) from 50 wt % to 20 wt % of the SL second ethylene/α-olefin copolymer having a density from 0.900 g/cc to 0.920 g/cc and a melt temperature from 95° C. to 105° C., wherein weight % is based on total weight of the skin layer (a).
3 . The laminate of claim 1 wherein the first intermediate layer (b) comprises (i) the FIL first ethylene/α-olefin copolymer having a density from 0.940 g/cc to 0.950 g/cc and a melt temperature from 125° C. to 129° C.; and (ii) the FIL second ethylene/α-olefin copolymer having a density from 0.955 g/cc to 0.980 g/cc and a melt temperature from 130° C. to 135° C.
4 . The laminate of claim 1 wherein the core layer (c) comprises (i) from 10 wt % to 50 wt % of the CL first ethylene/α-olefin copolymer having a density from 0.900 g/cc to 0.920 g/cc and a melt temperature from 120° C. to 125° C.; and (ii) from 90 wt % to 50 wt % of the CL second ethylene/α-olefin copolymer having a density from 0.940 g/cc to 0.980 g/cc, and a melt temperature from 125° C. to 130° C., wherein the weight % is based on the total weight of the core layer (c).
5 . The laminate of claim 1 wherein the second intermediate layer (d) comprises a second intermediate layer (SIL) first ethylene-based polymer having a density from 0.900 g/cc to 0.920 g/cc.
6 . The laminate of claim 1 wherein the interior layer (e) comprises an interior layer (IL) first ethylene/α-olefin copolymer having a density from 0.940 g/cc to 0.980 g/cc.
7 . The laminate of claim 1 wherein the 1MDO multilayer film comprises (a) the skin layer comprising (i) from 50 wt % to 80 wt % of the SL first ethylene/α-olefin copolymer having a density from 0.870 g/cc to 0.920 g/cc, and (ii) from 50 wt % to 20 wt % of the SL second ethylene/α-olefin copolymer having a density from 0.900 g/cc to 0.920 g/cc, where weight % is based on the total weight of the skin layer (a); (b) the first intermediate layer in direct contact with the skin layer, the first intermediate layer comprising (i) the FIL first ethylene/α-olefin copolymer having a density from 0.940 g/cc to 0.980 g/cc, and (ii) the FIL second ethylene/α-olefin copolymer having a density from 0.916 g/cc to 0.980 g/cc; and (c) the core layer in direct contact with the first intermediate layer, the core layer comprising (i) the CL first ethylene/α-olefin copolymer having a density from 0.900 g/cc to 0.920 g/cc, and (ii) a CL second ethylene/α-olefin copolymer having a density from 0.940 g/cc to 0.980 g/cc, where weight % is based on the total weight of the core layer (c); (d) the second intermediate layer in direct contact with the core layer, the second intermediate layer comprising an ethylene-based polymer; and (e) the interior layer in direct contact with the second intermediate layer, the interior layer comprising an ethylene-based polymer.
8 . The laminate of claim 1 wherein the 2MDO film is a multilayer film and comprises an outermost layer (ol) comprising an (ol) first ethylene/α-olefin copolymer having a density from 0.935 g/cc to 0.980 g/cc; and the adhesive layer is in direct contact with the interior layer (e) of the 1MDO multilayer film and the outermost layer (ol) of the 2MDO multilayer film.
9 . The laminate of claim 8 wherein the 2MDO multilayer film comprises the outermost layer (ol); an outer middle layer (om) in direct contact with the outer layer (ol); a middle layer (ml) in direct contact with the outer middle layer (om); an inner middle layer (im) in direct contact with the middle layer (ml); and an inner layer (in) in direct contact with the inner middle layer (im).
10 . The laminate of claim 9 wherein the 2MDO multilayer film is composed solely of one or more ethylene-based polymers.
11 . The laminate of claim 1 wherein the 1MDO multilayer film is composed solely of one or more ethylene-based polymers.
12 . The laminate of claim 1 comprising: a first skin layer (a) in contact with a second skin layer (a); a heat seal between the first skin layer (a) and the second skin layer (a); and the heat seal has a heat seal strength greater than or equal to 0.3 kg/25 mm under heat seal conditions of 2.5 kg/cm 2 seal pressure, a 0.5 seconds dwell time, and 95° C. seal temperature.

Description

FIELD The present disclosure relates to laminates, and more specifically, laminates comprising machine direction oriented multilayer films. BACKGROUND Polyolefin films are widely used in flexible packaging, either as stand-alone packaging or lamination film. In an effort to improve recyclability and expand sustainability, the flexible packaging market is moving toward mono-material solutions based on ethylene-based polymers (commonly referred to “polyethylenes”). As such, efforts continue to downgauge polyethylene films in search of thinner, tougher, stiffer and lower cost solutions for flexible packaging. Machine direction oriented (MDO) film is one approach for downgauging polyethylene and providing stiffness and optical properties to film. However, when oriented in the machine direction, polyethylene-based film can become weak in tear strength in the machine direction due to the unidirectional orientation. Polyethylene in films therefore is often blended with one or more non-polyethylene resins, or polyethylene films are often laminated with another non-polyethylene film (e.g., polyethylene terephthalate, polypropylene film) to achieve desirable physical film properties. Films including polyethylene and non-polyethylene resins, however, can be difficult or impossible to recycle. Likewise, while oriented polypropylene laminates with cast polypropylene structures may provide some desirable properties in packages, such laminates are not easily recyclable. Consequently, the art recognizes the need for laminates and MDO multilayer film comprising polyethylene that can be recycled and provide suitable tear strength, stiffness, optics, and heat sealability for flexible packaging applications. SUMMARY The present disclosure provides a laminate. In an embodiment, the laminate comprises a first machine direction oriented (1MDO) multilayer film. The 1MDO multilayer film comprises (a) a skin layer comprising (i) a skin layer (SL) first ethylene/α-olefin copolymer having a density from 0.870 g/cc to 0.920 g/cc, and (ii) an optional skin layer (SL) second ethylene/α-olefin copolymer having a density from 0.900 g/cc to 0.980 g/cc. The 1MDO multilayer film comprises (b) a first intermediate layer in direct contact with the skin layer. The first intermediate layer comprises (i) a first intermediate layer (FIL) first ethylene/α-olefin copolymer having a density from 0.940 g/cc to 0.980 g/cc, and (ii) a first intermediate layer (FIL) second ethylene/α-olefin copolymer having density from 0.916 g/cc to 0.980 g/cc. The 1MDO multilayer film comprises (c) a core layer in direct contact with the first intermediate layer (b). The core layer (c) comprises (i) a core layer (CL) first ethylene/α-olefin copolymer having a density from 0.915 g/cc to 0.980 g/cc. The 1MDO multilayer film comprises (d) a second intermediate layer in direct contact with the core layer. The second intermediate layer comprises an ethylene-based polymer. The 1MDO multilayer film comprises (e) an interior layer in direct contact with the second intermediate layer. The interior layer comprises an ethylene-based polymer. The laminate comprises a second machine direction oriented (2MDO) film and an adhesive layer between the 1MDO multilayer film and the 2MDO film. Definitions Any reference to the Periodic Table of Elements is that as published by CRC Press, Inc., 1990-1991. Reference to a group of elements in this table is by the new notation for numbering groups. For purposes of United States patent practice, the contents of any referenced patent, patent application or publication are incorporated by reference in their entirety (or its equivalent U.S. version is so incorporated by reference) especially with respect to the disclosure of definitions (to the extent not inconsistent with any definitions specifically provided in this disclosure). The numerical ranges disclosed herein include all values from, and including, the lower and upper value. For ranges containing explicit values (e.g., from 1 or 2, or 3 to 5, or 6, or 7), any subrange between any two explicit values is included (e.g., the range 1-7 above includes subranges of from 1 to 2; from 2 to 6; from 5 to 7; from 3 to 7; from 5 to 6; etc.). Unless stated to the contrary, implicit from the context, or customary in the art, al parts and precents are based on weight and all test methods are current as of the filing date of this disclosure. The terms “blend” or “polymer blend,” as used, refers to a mixture of two or more polymers. A blend may or may not be miscible (not phase separated at molecular level). A blend may or may not be phase separated. A blend may or may not contain one or more domain configurations, as determined from transmission electron spectroscopy, light scattering, x-ray scattering, and other methods known in the art. The blend may be affected by physically mixing the two or more polymers on the macro level (for example, melt blending resins or compounding), or the micro level (for exa