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US-12617191-B2 - Multilayer polyolefin films and methods for their production

US12617191B2US 12617191 B2US12617191 B2US 12617191B2US-12617191-B2

Abstract

Multilayer films comprising polyolefins and products comprising the multilayer films are disclosed. These multilayer films have fewer defects, especially optical defects.

Inventors

  • Venu M. KONDURU
  • John E. Kovalchuk
  • Meng Li
  • Hoang T. Pham
  • Jihui SHANG

Assignees

  • AVERY DENNISON CORPORATION

Dates

Publication Date
20260505
Application Date
20220228

Claims (5)

  1. 1 . A multilayer film, comprising: a core layer having a first side and second side; a first skin layer on the first side of the core layer; a second skin layer on the second side of the core layer; a first tie coat between the core layer and the first skin layer; and a second tie coat between the core layer and the second skin layer; wherein the multilayer film is oriented only in a machine direction; and wherein the multilayer film is cavitated; wherein the first tie layer and the second tie layer each comprise: about 60% by weight to about 99.8% by weight, based on the total weight of the tie layer, polypropylene; about 0.1% by weight to about 10% by weight, based on the total weight of the tie layer, ethylene vinyl acetate; and about 0.1% by weight to about 20% by weight, based on the total weight of the tie layer, filler.
  2. 2 . A multilayer film of claim 1 , wherein the first tie layer and the second tie layer each comprise non-post-consumer waste recycled content.
  3. 3 . A multilayer film of claim 1 , wherein the first tie layer and the second tie layer each comprise up to about 50% by weight, based on the total weight of the tie layer, non-post-consumer waste recycled content.
  4. 4 . The multilayer film of claim 1 , further comprising: printed indicia on at least a portion of the first skin.
  5. 5 . A product, comprising: the multilayer film of claim 1 ; an adhesive layer on at least a portion of the second skin layer on a side opposite to the core layer; and an optional release liner on the adhesive layer.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a 371 of International Application No. PCT/US2022/018081, which was published in English on Sep. 9, 2022, and claims priority to U.S. Application No. 63/157,221 filed Mar. 5, 2021, the entire contents of which are herein incorporated by reference in their entireties. FIELD OF THE INVENTION The present invention generally relates to multilayer films and, more particularly, to multilayer films comprising polyolefins and products comprising the multilayer films. BACKGROUND OF THE INVENTION Multilayer films comprising polyolefins and products comprising the multilayer films are used in labels that provide information and/or decoration when printed. Defects in the multilayer film can cause issues with the ability to properly perceive the information or decoration on the substrate, such as a container, to which the label is applied. It is also important for proper branding and can be representative of quality of the contents of the container. Thus, it is desirable that the label not have any defects. The multilayer films and products comprising the multilayer films of the present invention are directed toward these, as well as other, important ends. SUMMARY OF THE INVENTION The invention relates generally to multilayer films comprising polyolefins and products comprising the multilayer films, especially those that have fewer visual defects. In one aspect, the invention is directed to multilayer films, comprising: a core layer having a first side and second side;a first skin layer on the first side of the core layer;a second skin layer on the second side of the core layer;a first tie coat between the core layer and the first skin layer; anda second tie coat between the core layer and the second skin layer;wherein the first tie layer and the second tie layer each comprise at least 95% by weight, based on the weight of the tie layer, polypropylene and substantially no white pigment; andwherein the multilayer film is cavitated. In another aspect, the invention is directed to a core layer having a first side and second side; a first skin layer on the first side of the core layer;a second skin layer on the second side of the core layer;a first tie coat between the core layer and the first skin layer; anda second tie coat between the core layer and the second skin layer;wherein the first tie layer and the second tie layer;wherein the multilayer film is oriented in a machine direction; andwherein the multilayer film is cavitated;wherein the first tie layer and the second tie layer each comprise:about 60% by weight to about 100% by weight, based on the total weight of the skin layer, polypropylene;about 0.1% by weight to about 10% by weight, based on the total weight of the skin layer, ethylene vinyl acetate;about 0.1% by weight to about 20% by weight, based on the total weight of the skin layer, filler; andabout 0.1% by weight to about 5% by weight, based on the total weight of the skin layer, filler. In yet other aspects, the invention is directed to products, comprising: the multilayer film described herein; andan adhesive layer on at least a portion of the second skin layer on a side opposite to the core layer; andan optional release liner on the adhesive layer. The summary of the invention is provided as a general introduction to some of the embodiments of the invention, and is not intended to be limiting. Additional example embodiments, including variations and alternative configurations, of the invention are provided herein. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. As will be realized, the subject matter described herein is capable of other and different embodiments and its several details are capable of modifications in various respects, all without departing from the claimed subject matter. Accordingly, the drawings and description are to be regarded as illustrative and not restrictive. In the drawings: FIG. 1 illustrates one embodiment of the multilayer films of the invention. FIG. 2 illustrates one embodiment of the products comprising a multilayer film of the invention. DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS Definitions As employed above and throughout the disclosure, the following terms, unless otherwise indicated, shall be understood to have the following meanings. As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended are open-ended and cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such