JP-7854775-B2 - Substrates, vapor-deposited substrates, laminates, and packaging containers

JP7854775B2JP 7854775 B2JP7854775 B2JP 7854775B2JP-7854775-B2

Inventors

山田憲一

Assignees

大日本印刷株式会社

Dates

Publication Date: 20260507
Application Date: 20200331

Claims (15)

A vapor deposition substrate comprising at least a substrate and a vapor-deposited film, The substrate comprises at least a polyethylene resin layer and a surface resin layer provided on one surface of the polyethylene resin layer. The aforementioned substrate is a co-extruded film, The aforementioned surface resin layer contains a resin material having a melting point of 150°C or higher. The aforementioned substrate has been subjected to a stretching treatment. The vapor-deposited film is provided on the surface resin layer of the substrate, A vapor deposition substrate further comprising a barrier coating layer provided on the vapor-deposited film.
The vapor deposition substrate according to claim 1, wherein the surface resin layer comprises a resin material having a melting point of 150°C or higher and 265°C or lower.
The vapor deposition substrate according to claim 1 or 2, wherein the difference in melting points between the polyethylene resin and the resin material of the surface resin layer having a melting point of 150°C or higher is 20 to 80°C.
The vapor deposition substrate according to any one of claims 1 to 3, wherein the resin material of the surface resin layer is a polymer having polar groups.
The vapor deposition substrate according to any one of claims 1 to 4, wherein the resin material of the surface resin layer is at least one resin material selected from the group consisting of ethylene vinyl alcohol copolymer, polyvinyl alcohol, polyester, nylon 6, nylon 6,6, nylon 6-nylon 6,6 copolymer, MXD nylon, and amorphous nylon.
The vapor- deposited substrate according to any one of claims 1 to 5, wherein the ratio of the thickness of the surface resin layer to the total thickness of the substrate is 2% or more and 20% or less.
The vapor deposition substrate according to any one of claims 1 to 6, wherein the polyethylene resin layer has a multilayer structure.
The vapor deposition substrate according to any one of claims 1 to 7, wherein the polyethylene resin layer comprises at least one layer containing a compatibilizer.
The vapor deposition substrate according to claim 8, wherein the layer in contact with the surface resin layer of the polyethylene resin layer further comprises a compatibilizer.
A vapor-deposited substrate according to any one of claims 1 to 9, used in packaging containers.
A laminate comprising a vapor-deposited substrate and a sealant layer according to any one of claims 1 to 10 .
The laminate according to claim 11 , wherein the sealant layer is made of polyethylene resin.
A packaging container comprising a laminate according to claim 11 or 12 .
The packaging container according to claim 13 , wherein the polyethylene resin content in the entire laminate is 80% by mass or more.
A packaging container according to claim 13 or 14 , which is a packaging bag.

Description

This invention relates to a substrate, a vapor-deposited substrate, a laminate, and a packaging container. Conventionally, resin films made from polyester resins such as polyethylene terephthalate (hereinafter also referred to as polyester films) have been used in the manufacture of packaging containers because they have excellent mechanical properties, chemical stability, heat resistance, and transparency, as well as being inexpensive. Such polyester films are used as a base material and are typically laminated with a polyethylene film, which serves as a sealant layer, to form a laminate that is then molded into a packaging container. The packaging containers obtained by forming laminates of different types of resin films, namely polyester film and polyethylene film, are difficult to separate into their individual layers. Therefore, these used packaging containers are not suitable for recycling and are not actively recycled. In light of this situation, and with the aim of improving the recyclability of packaging containers, the use of stretched polyethylene film (stretched polyethylene film) as the base material instead of polyester film, and the production of packaging containers using laminates composed of the same material (monomaterial packaging containers) are being considered. This is a schematic cross-sectional view showing one embodiment of the substrate of the present invention.This is a schematic cross-sectional view showing one embodiment of the substrate of the present invention.This is a schematic cross-sectional view showing one embodiment of the laminate of the present invention.This is a schematic cross-sectional view showing one embodiment of the laminate of the present invention.This is a schematic cross-sectional view showing one embodiment of a vapor deposition apparatus.This is a schematic cross-sectional view showing one embodiment of a vapor deposition apparatus.This is a schematic cross-sectional view showing one embodiment of a laminate used in the manufacture of a packaging container.This is a front view showing one embodiment of the packaging container of the present invention.This is a perspective view showing one embodiment of the packaging container of the present invention.This is a front view showing one embodiment of the packaging container of the present invention.This is a cross-sectional view taken along line a-a in Figure 10. (Base material) As shown in Figure 1, the base material 10 of the present invention comprises a polyethylene resin layer 11 and a surface resin layer 12 containing a resin material with a melting point of 150°C or higher. A substrate having such a configuration can be suitably used as a substrate for monomaterial packaging containers, and the adhesion between the layers with the vapor-deposited film is significantly improved, resulting in a substrate with high gas barrier properties. In one embodiment, as shown in Figure 2, the base material 10 may further include an adhesive resin layer 13 between the polyethylene resin layer 11 and the surface resin layer 12. The ratio of the thickness of the surface resin layer to the total thickness of the substrate is preferably 2% to 20%, and more preferably 4% to 15%. By setting the ratio of the surface resin layer thickness to the total thickness of the substrate to 2% or more, the adhesion of the vapor-deposited film can be further improved, and the gas barrier properties of the substrate on which the vapor-deposited film is formed can be further improved. Furthermore, by setting the ratio of the surface resin layer thickness to the total thickness of the base material to 20% or less, the base material can be made suitable for use in the manufacture of monomaterial packaging containers. In addition, the film-forming properties and processability of the base material can be further improved. In this invention, the substrate is characterized by being subjected to a stretching treatment. This improves the strength and heat resistance of the substrate. It also improves printability. The stretching process may be uniaxial stretching or biaxial stretching. The stretching ratio of the substrate in the longitudinal direction (MD direction) and transverse direction (TD direction) is preferably 2 times or more and 15 times or less, and preferably 5 times or more and 13 times or less. By increasing the stretching ratio to 2 times or more, the strength and heat resistance of the substrate can be further improved. Furthermore, the printability of the substrate can be improved. Furthermore, from the viewpoint of the breaking limit of the substrate, it is preferable that the stretch ratio is 15 times or less. In one embodiment, the substrate of the present invention is a co-extruded film. Furthermore, in one embodiment, the substrate of the present invention can be produced by forming a film using a T-die method or an inflation method, forming a resin film, and then stretching it. Furthermore, by forming the film using t