US-12617188-B2 - Laminate and package

US12617188B2US 12617188 B2US12617188 B2US 12617188B2US-12617188-B2

Abstract

This laminate has an inner layer formed of a polyethylene-based resin, an outer layer formed of a polyethylene-based resin, and a barrier layer laminated between the inner layer and the outer layer. The inner layer is formed as a sealant layer that is an innermost layer of the laminate, and the barrier layer is laminated in contact with an outer surface of the inner layer. Accordingly, it is possible to provide a laminate and a package which are formed of a mono-material and have a barrier property.

Inventors

Toshihiko Mori
Naoto Fujikawa
Hiroshi Kuwabara

Assignees

FUJIMORI KOGYO CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20211025
Priority Date: 20201026

Claims (7)

1 . A laminate comprising: an inner layer formed of linear low-density polyethylene (LLDPE) or low-density polyethylene (LDPE); an outer layer formed of medium-density polyethylene (MDPE) or high-density polyethylene (HDPE); and a barrier layer laminated between the inner layer and the outer layer, wherein the inner layer is formed as a sealant layer that is an innermost layer of the laminate and is configured for joining the laminate, wherein the barrier layer is laminated in contact with an outer surface of the inner layer, wherein the barrier layer is a barrier coat layer formed by reacting a crosslinkable compound with reactive functional groups of a polymer compound to crosslink the polymer compound, and wherein the barrier layer and the outer layer are laminated via an adhesive layer.
2 . The laminate according to claim 1 , wherein films included in the laminate are only the inner layer and the outer layer.
3 . The laminate according to claim 1 , wherein a base layer included in the laminate is only the outer layer.
4 . The laminate according to claim 1 , wherein the inner layer is formed of non-oriented linear low-density polyethylene (LLDPE) or non-oriented low-density polyethylene (LDPE), and the outer layer is formed of oriented medium-density polyethylene (MDPE) or oriented high-density polyethylene (HDPE).
5 . The laminate according to claim 1 , wherein a thickness of the barrier layer is 5 μm or less.
6 . The laminate according to claim 1 , wherein a printing layer is laminated between the barrier layer and the outer layer.
7 . A package formed of the laminate according to claim 1 .

Description

FIELD OF THE INVENTION The present invention relates to a laminate and a package. Priority is claimed on Japanese Patent Application No. 2020-178893, filed Oct. 26, 2020, the content of which is incorporated herein by reference. BACKGROUND OF THE INVENTION In paragraph 0012 of Japanese Unexamined Patent Application, First Publication No. 2010-265020 and paragraph 0010 of Japanese Unexamined Patent Application, First Publication No. 2013-265020, as a film used for a packaging bag in the related art, a laminated film obtained by laminating a polyolefin-based resin such as low-density polyethylene, linear low-density polyethylene, an ethylene-vinyl acetate copolymer, and polypropylene as a sealant layer on a base film such as biaxially oriented polypropylene, biaxially oriented polyamide, and biaxially oriented polyester is described. SUMMARY OF THE INVENTION Technical Problem In recent years, regarding the recovery of used plastic container or packages, there is a problem that a packaging bag containing two or more resins is difficult to recycle as a plastic container or package. To facilitate recycling, mono-material container packages using a single resin have been proposed. As a single resin, a polyethylene-based resin is inexpensive and easy to process, but has the problem of a poor barrier property and easy penetration of low-molecular-weight components such as perfumes. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laminate (laminated sheet) and a package which are formed of a mono-material and have a barrier property. Solution to Problem In order to solve the above problems, a laminate according to the present invention includes: an inner layer formed of a polyethylene-based resin; an outer layer formed of a polyethylene-based resin; and a barrier layer laminated between the inner layer and the outer layer, wherein the inner layer is formed as a sealant layer that is an innermost layer of the laminate, and wherein the barrier layer is laminated in contact with an outer surface of the inner layer. The barrier layer may be a barrier coat layer formed on the outer surface of the inner layer. The films included in the laminate may be only the inner layer and the outer layer formed of a polyethylene-based resin film. A base layer included in the laminate may be only the outer layer formed of a polyethylene-based resin. The inner layer may be formed of a non-oriented polyethylene-based resin, and the outer layer may be formed of an oriented polyethylene-based resin. A thickness of the barrier layer may be 5 μm or less. The barrier layer and the outer layer may be laminated via an adhesive layer. A printing layer may be laminated between the barrier layer and the outer layer. Moreover, a package according to the present invention is formed of the laminate. Advantageous Effects of Invention According to the present invention, it is possible to provide a laminate and a package which are formed of a mono-material and have a barrier property. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged cross-sectional view showing an embodiment of a laminate of the present invention. FIG. 2 is a front view showing an embodiment of a package of the present invention. DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below on the basis of preferred embodiments. A laminate of an embodiment has an inner layer formed of a polyethylene-based resin, an outer layer formed of a polyethylene-based resin, and a barrier layer laminated between the inner layer and the outer layer. FIG. 1 is an enlarged cross-sectional view showing a laminate 1 that is an example of the present embodiment. The laminate (laminated sheet) 1 has an inner layer 2, an outer layer 4, and a barrier layer 6 laminated between the inner layer 2 and the outer layer 4. FIG. 2 is a front view showing a standing pouch 10 as an example of a package using the laminate 1. This standing pouch 10 includes a hollow container body 12 and a spout member 14 attached to one end of the container body 12. The container body 12 is formed of, for example, two rectangular body films 16 having the same planar shape and a bottom film 18. Both the body film 16 and the bottom film 18 are formed of the laminate 1, and the outer edges of the inner layers 2 are heat-sealed to each other to form a heat-sealed portion 20. As a result, the container body 12 has a bag-like shape as a whole, and contents can be put into and taken out of the container body 12 through the spout member 14. In a state where no contents are put in, the container body 12 is crumpled and flattened. The present invention is not limited to the standing pouch but can be applied to various packages using a laminate, and can provide a package which is formed of a mono-material and has a good barrier property. The inner layer is disposed as the innermost layer on the inner surface of the laminate. The inner lay