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EP-4741311-A1 - AIR-PERMEABLE PACKAGING MATERIAL FOR OXYGEN SCAVENGER AND METHOD FOR MANUFACTURING SAME

EP4741311A1EP 4741311 A1EP4741311 A1EP 4741311A1EP-4741311-A1

Abstract

An air-permeable packaging material for an oxygen scavenger includes, in this order, an outer layer containing a thermoplastic resin, an intermediate layer containing one or more selected from paper and nonwoven fabric, and an inner layer containing a linear low-density polyethylene, the inner layer includes a through-hole H1, the through-hole H1 having an opening diameter φ1 of 150 µm or more and 3000 µm or less, and when differential scanning calorimetry is performed using the inner layer as a measurement sample in a nitrogen atmosphere under conditions of heating from 50°C to 200°C at 10°C per minute (heating 1), then cooling from 200°C to 50°C at 10°C per minute (cooling 1), and heating again from 50°C to 200°C at 10°C per minute (heating 2), a maximum endothermic peak is observed at 120°C or more in a process of (heating 2).

Inventors

  • SATO, DAIKI
  • MASUYAMA, Tomohiro
  • Watanabe, Risa

Assignees

  • MITSUBISHI GAS CHEMICAL COMPANY, INC.

Dates

Publication Date
20260513
Application Date
20240627

Claims (9)

  1. An air-permeable packaging material for an oxygen scavenger, comprising, in this order, an outer layer containing a thermoplastic resin, an intermediate layer containing one or more selected from paper and nonwoven fabric, and an inner layer containing a linear low-density polyethylene, wherein the inner layer includes a through-hole H1, the through-hole H1 having an opening diameter φ1 of 150 µm or more and 3000 µm or less, and when differential scanning calorimetry is performed using the inner layer as a measurement sample in a nitrogen atmosphere under conditions of heating from 50°C to 200°C at 10°C per minute (heating 1), then cooling from 200°C to 50°C at 10°C per minute (cooling 1), and heating again from 50°C to 200°C at 10°C per minute (heating 2), a maximum endothermic peak is 120°C or more in a process of (heating 2).
  2. The air-permeable packaging material for an oxygen scavenger according to claim 1, wherein the intermediate layer includes an oil-resistant paper containing no fluorine.
  3. The air-permeable packaging material for an oxygen scavenger according to claim 1 or 2, having an air resistance of 10000 seconds or more as measured by an Oken type tester method in accordance with JIS P8117:2009.
  4. The air-permeable packaging material for an oxygen scavenger according to any one of claims 1 to 3, wherein the through-hole H1 is present at a density of 1 hole/cm 2 or more and 60 holes/cm 2 or less.
  5. The air-permeable packaging material for an oxygen scavenger according to any one of claims 1 to 4, wherein the intermediate layer has an air resistance of 2000 seconds or less as measured by an Oken type tester method in accordance with JIS P8117:2009.
  6. The air-permeable packaging material for an oxygen scavenger according to any one of claims 1 to 5, wherein the intermediate layer is an oil-resistant paper containing no fluorine.
  7. The air-permeable packaging material for an oxygen scavenger according to any one of claims 1 to 6, wherein the outer layer includes, in this order toward an intermediate layer side, a substrate layer containing one or more selected from polyethylene terephthalate and biaxially oriented polypropylene and a welding layer containing one or more selected from polyethylene and an ethylene copolymer.
  8. An oxygen scavenger package, comprising: the air-permeable packaging material for an oxygen scavenger according to any one of claims 1 to 7; and an oxygen scavenger wrapped by the air-permeable packaging material for an oxygen scavenger.
  9. A method for producing an air-permeable packaging material for an oxygen scavenger, the method comprising: obtaining an inner layer by pressing a heated metal needle against a film containing a linear low-density polyethylene to form a through-hole H1; and obtaining an air-permeable packaging material for an oxygen scavenger by laminating an outer layer containing a thermoplastic resin, an intermediate layer containing one or more selected from paper and nonwoven fabric, and the inner layer in this order, wherein the metal needle has a radius of 0.3 mm or more and 2.0 mm or less, the metal needle has a surface temperature of 150°C or more and 450°C or less, and when differential scanning calorimetry is performed using the inner layer as a measurement sample in a nitrogen atmosphere under conditions of heating from 50°C to 200°C at 10°C per minute (heating 1), then cooling from 200°C to 50°C at 10°C per minute (cooling 1), and heating again from 50°C to 200°C at 10°C per minute (heating 2), a maximum endothermic peak observed is at 120°C or more in a process of (heating 2).

Description

Technical Field The present invention relates to an air-permeable packaging material for an oxygen scavenger and a method for producing the same. Background Art For various articles such as food products, beverages, medical and pharmaceutical products, medical supplies, cosmetics, metal products and electronic products that easily deteriorate or degrade under the effect of oxygen, an oxygen scavenger that removes oxygen in a sealed container containing these has been used to prevent oxidation degradation and to enable storage for a long period of time. The oxygen scavenger has been employed in various manners based on the purpose or the form of use thereof, and an example thereof is a method of forming a pouch-shaped oxygen scavenger package by packaging an oxygen scavenger, which is in powder or tablet form, in a packaging material. When this oxygen scavenger package is placed in a sealed container storing a food product or the like, oxidation degradation of the food product or the like can be prevented because the oxygen scavenger in an inner part of the oxygen scavenger package removes oxygen in the sealed container. As such a packaging material for an oxygen scavenger, for example, sheets of a resin, paper, nonwoven fabric, or the like or a laminate of these has been used. As a packaging material, in which a resin layer and a layer of paper or nonwoven fabric are laminated, for example, a packaging material obtained by laminating a resin layer having an air hole formed in advance and a layer of paper or nonwoven fabric has been used. This attempts to ensure air permeability with the outside and effectively exhibit oxygen scavenging performance of the oxygen scavenger by using the resin layer having a vent hole formed in advance. However, a known air-permeable packaging material for an oxygen scavenger has a problem that the deoxidation time is not stable. One of the reasons for this problem is considered to be that the air permeance of the air-permeable packaging material is not stable. Therefore, in order to solve such a problem, Patent Document 1 proposes a technique of facilitating control of a target value of air permeance of an air-permeable packaging material by using an air-permeable packaging material subjected to special processing. Citation List Patent Document Patent Document 1: JP 2004-082460 A Summary of Invention Technical Problem Since the special processing as proposed in Patent Document 1 requires apparatus and conditions suitable for the processing, existing manufacturing apparatus and manufacturing conditions cannot be used as they are, resulting in complexity of the processing and a significant burden on the manufacturer. Therefore, there has been a demand for development of an air-permeable packaging material for an oxygen scavenger that can exhibit stable oxygen absorption performance with little individual difference by using existing manufacturing apparatus and manufacturing conditions without use of special manufacturing apparatus. The present invention has been made in view of such circumstances, and an object of the present invention is to provide an air-permeable packaging material for an oxygen scavenger and a method for producing the same, the air-permeable packaging material being capable of providing an oxygen scavenger package that can exhibit excellent oxygen absorption performance with short deoxidation time and stable oxygen absorption performance with little individual difference by using existing manufacturing apparatus and manufacturing conditions without use of special manufacturing apparatus. Solution to Problem The present inventors have found that the above object can be achieved when an air-permeable packaging material for an oxygen scavenger includes an outer layer, an intermediate layer, and an inner layer, in which the inner layer is made of a specific material and has specific through-holes, and have thus completed the invention. That is, the gist of constituents of the present invention includes the following: [1] An air-permeable packaging material for an oxygen scavenger, including, in this order, an outer layer containing a thermoplastic resin, an intermediate layer containing one or more selected from paper and nonwoven fabric, and an inner layer containing linear low-density polyethylene, in which the inner layer includes a through-hole H1, the through-hole H1 having an opening diameter φ1 of 150 µm or more and 3000 µm or less, andwhen differential scanning calorimetry is performed using the inner layer as a measurement sample in a nitrogen atmosphere under conditions of heating from 50°C to 200°C at 10°C per minute (heating 1), then cooling from 200°C to 50°C at 10°C per minute (cooling 1), and heating again from 50°C to 200°C at 10°C per minute (heating 2), a maximum endothermic peak is observed at 120°C or more in a process of (heating 2).[2] The air-permeable packaging material for an oxygen scavenger according to [1] above, in which the intermed