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JP-2026075450-A - packaging

JP2026075450AJP 2026075450 AJP2026075450 AJP 2026075450AJP-2026075450-A

Abstract

[Problem] To provide a package that ensures sufficient airtightness at the heat-sealed portion between the flange portion of the container and the outer edge of the lid material, while also improving ease of opening. [Solution] The packaging body 1 consists of a container 2 and a lid material 3 heat-sealed to the flange portion 21 of the container 2. The container 2 comprises a barrier layer 41, a container-side heat-seal layer 42 provided on one side of the barrier layer 41, and a protective layer 43 provided on the other side of the barrier layer 41. The lid material 3 comprises a base material layer 51 and a lid material-side heat-seal layer 52 provided on one side of the base material layer 51. The flange portion 21 of the container 2 and the lid material 3 are heat-sealed using the container-side heat-seal layer 42 and the lid material-side heat-seal layer 52. The thickness of the container-side heat-seal layer 42 in the portion of the container 2 that is not heat-sealed to the lid material 3 is 20 to 50 μm, and the overall thickness of the portion of the lid material 3 that is not heat-sealed to the flange portion 21 of the container 2 is 30 to 80 μm. [Selection Diagram] Figure 3

Inventors

  • 田中 優樹
  • 長岡 孝司

Assignees

  • 株式会社ＤＮＰ高機能マテリアル彦根

Dates

Publication Date
20260508
Application Date
20241022

Claims (6)

  1. A packaging comprising a cup-shaped container having an outward-facing flange around its opening and containing contents, and a lid material whose outer periphery is heat-sealed to the flange of the container so as to cover the opening of the container, wherein the container comprises a barrier layer, a container-side heat-seal layer provided on one side of the barrier layer and covering the lid material side of the flange, and a protective layer provided on the other side of the barrier layer, and the lid material comprises a base layer and a lid material-side heat-seal layer provided on one side of the base layer and covering the container material side of the lid, and the flange of the container and the lid material are heat-sealed using the container-side heat-seal layer and the lid material-side heat-seal layer, A packaging body in which the container-side heat seal layer contains a single-layer unstretched film made of a mixture of 50 to 70 parts by weight of at least one of a propylene-ethylene random copolymer and a propylene-ethylene-butene random copolymer having an MFR of 2.0 to 8.0 g/10 min and a melting point of 130 to 145°C, 20 to 40 parts by weight of a low-density polyethylene resin having an MFR of 2.0 to 10.0 g/10 min and a density of 0.910 to 0.925 g/cm³, and 2 to 20 parts by weight of a linear low-density polyethylene resin having an MFR of 1.5 to 4.5 g/10 min and a density of 0.915 to 0.940 g/cm³, wherein the unstretched film is heat-sealed to the lid-side heat seal layer, and the thickness of the container-side heat seal layer in the portion of the container not heat-sealed to the lid is 20 to 50 μm.
  2. The packaging according to claim 1, wherein the linear low-density polyethylene resin of the unstretched film heat-sealed to the heat-seal layer on the lid side is made of an ethylene-hexene copolymer.
  3. The packaging according to claim 1, wherein a single layer of unstretched film made of a propylene-ethylene random copolymer with an MFR of 3.0 to 11.0 g/10 min and a melting point of 150 to 160°C is laminated on the barrier layer side of the single layer of unstretched film that is heat-fused to the lid material side heat seal layer in the container side heat seal layer, resulting in a two-layer structure for the container side heat seal layer.
  4. The packaging according to claim 1, wherein a single layer of unstretched film is laminated on the barrier layer side of the single layer of unstretched film that is heat-fused to the lid material side heat seal layer in the container side heat seal layer, the single layer of unstretched film consisting of a mixture of 60 to 100 parts by weight of a propylene-ethylene random copolymer with an MFR of 3.0 to 11.0 g/ 10 min and a melting point of 150 to 160°C and 5 to 45 parts by weight of a linear low-density polyethylene resin with an MFR of 1.5 to 4.5 g/10 min and a density of 0.915 to 0.940 g/cm³, and the container side heat seal layer has a two-layer structure.
  5. The packaging according to claim 4, wherein the linear low-density polyethylene resin of the unstretched film laminated on the barrier layer side of the unstretched film, which is heat-sealed to the heat-seal layer on the lid side, is made of an ethylene-hexene copolymer.
  6. The packaging according to claim 3 or 4, wherein the thickness of the unstretched film heat-sealed to the lid-side heat-seal layer in the container-side heat-seal layer is thinner than the thickness of the unstretched film on the barrier layer side.

Description

This invention relates to a packaging body for sealing food, pharmaceuticals, electronic components, industrial products, and the like as its contents. In this specification and claims, the MFR (melt flow rate) of polypropylene resins was measured using the method specified in JIS K7210-1:2014 under conditions of a test temperature of 230°C and a load of 2.16 kg, and the MFR (melt flow rate) of polyethylene resins was measured using the method specified in JIS K7210-1:2014 under conditions of a test temperature of 190°C and a load of 2.16 kg. Similarly, the density was measured using the liquid weighing method specified in JIS Z8807:2012, and the melting point was measured using the differential scanning calorimetry method specified in JIS 7121:1987 under a heating rate of 10°C/min. In this specification, the top and bottom of Figures 2 to 7 shall be referred to as "top and bottom." Furthermore, in this specification, the term "aluminum" shall include aluminum alloys in addition to pure aluminum. For sealing and packaging liquid foods such as beverages, semi-solid foods such as puddings, jellies, yogurts, butter, and jams, oil- or liquid-containing foods such as curry, tuna, and soups, pharmaceuticals such as oral and transdermal drugs, pharmaceuticals requiring sterile packaging, viscous industrial products such as grease, adhesives, and sealants, and liquid industrial products such as oils that require long-term storage or prevention of quality deterioration, a widely used packaging system consists of a cup-shaped container with an outward-facing flange around the opening and the contents inside, and a lid material whose outer edge is heat-sealed to the flange of the container to cover the opening. Such packaging requires a secure seal between the container flange and the lid to enhance airtightness. This can lead to excessively strong seals, potentially reducing ease of opening. Therefore, packaging materials that ensure sufficient airtightness between the container flange and the lid while improving ease of opening are described in Patent Documents 1 and 2. The packaging described in Patent Document 1 has a heat-sealed surface (upper surface) of the flange portion of the container made of polyester resin or polycarbonate resin. The lid material consists of a base layer, a release layer provided on one side of the base layer, and a lid-side heat-seal layer provided on the side of the release layer opposite to the base layer. The outer edge of the lid material is heat-sealed to the upper surface of the flange portion of the container using the lid-side heat-seal layer. When the packaging of Patent Document 1 is opened, the portion of the lid-side heat-seal layer that is heat-sealed to the flange portion of the container peels off from the release layer and remains on the flange portion side of the container. The packaging described in Patent Document 2 comprises a container with a base layer and a container-side heat seal layer provided on one side of the base layer that forms the upper surface of the flange, and a lid with a base layer and a lid-side heat seal layer made of a multilayer film provided on one side of the base layer. The outer edge of the lid is heat-sealed to the upper surface of the container's flange using the container-side heat seal layer and the lid-side heat seal layer. An opening notch is formed on the upper surface of the container's flange, outside the heat-sealed portion between the flange and the lid, with a depth greater than or equal to the thickness of the resin film on the lid side of the container-side heat seal layer. When the packaging of Patent Document 2 is opened, the portion of the resin film on the lid side of the container-side heat seal layer outside the opening notch peels away from the adjacent resin film and remains on the lid side. Patent No. 4811083Patent No. 6738625 This is a perspective view showing an embodiment of the packaging according to this invention.Figure 1 is a vertical cross-sectional view of the packaging.This is an enlarged view of the main part of Figure 2.This diagram is equivalent to Figure 3, showing the state of opening the lid.This figure, equivalent to Figure 3, shows a modified example of the heat-seal layer on the container side used in the packaging container shown in Figure 1.This figure, corresponding to Figure 4, shows one aspect of opening the lid of a packaged body equipped with a heat-sealed layer on the container side, as shown in Figure 5.This figure, corresponding to Figure 4, shows another aspect of opening the lid of a package equipped with a heat-sealed layer on the container side, as shown in Figure 5. The embodiments of this invention will be described below with reference to the drawings. Figure 1 shows the overall structure of the packaging body according to this invention, and Figures 2 to 4 show the structure of the main parts. In Figures 1 and 2, the packaging (1) consists of a cup-shaped container (2) containing con