CN-122003325-A - Gas barrier laminate and packaging material

Abstract

A gas barrier laminate comprising (A) a layer formed of an olefin-based substrate having an inorganic layer formed on at least one surface, and (B) a layer comprising an ammonium salt of a resin having a carboxyl group and a polyvalent metal compound having a carboxyl group of 0.1 to 0.5 chemical equivalent relative to the carboxyl group of the ammonium salt of the resin having a carboxyl group, wherein the layer (B) comprises an ammonium salt of a resin (P1) having a weight average molecular weight of 3,000 to 200,000 and an ammonium salt of a resin (P2) having a weight average molecular weight of 200,000 to 10,000,000 in the range of P2/P1=10 to 2000.

Inventors

• KANDA RYO
• HARADA TOMOAKI

Assignees

• DIC株式会社

Dates

Publication Date

20260508

Application Date

20241010

Priority Date

20231026

Claims (7)

1. 1. A gas barrier laminate characterized by comprising: (A) A layer (A) formed of an olefin-based substrate having an inorganic layer formed on at least one surface, and (B) A layer (B) containing an ammonium salt of a resin having a carboxyl group and a polyvalent metal compound having a chemical equivalent of 0.1 to 0.5 to the carboxyl group of the ammonium salt of the resin having a carboxyl group, The layer (B) contains an ammonium salt of a resin (P1) having a carboxyl group and a weight average molecular weight of 3,000-200,000 and an ammonium salt of a resin (P2) having a carboxyl group and a weight average molecular weight of 200,000-10,000,000 in the range of P2/P1=10-2000.
2. 2. The gas barrier laminate according to claim 1, wherein the layer (B) contains 0.04 to 15 mass% of a hydroxyl group-containing compound having a boiling point of 120 ℃ or more relative to the solid content of the layer (B).
3. 3. The gas barrier laminate according to claim 1, wherein the layer (B) contains 10 to 30 mass% of at least one compound (S) selected from the group consisting of a silicon compound represented by the general formula (S1) and a hydrolysate thereof, (R 1 O) 3 Si-(CH 2 ) n -R 2 ·····(s1) In the general formula (s 1), R 1 represents an alkyl group, R 2 represents an organic group having an epoxy group or an amino group, and n represents an integer of 1 to 10.
4. 4. The gas barrier laminate according to claim 1, wherein the inorganic layer in the (a) layer is formed by any one of vapor deposition treatment or sputtering treatment.
5. 5. The gas barrier laminate according to claim 1, wherein the inorganic layer in the layer (a) is formed of one or more inorganic substances selected from the group consisting of aluminum oxide, silicon oxide, aluminum, zinc oxide, and magnesium oxide.
6. 6. A packaging material comprising the gas barrier laminate according to any one of claims 1 to 5.
7. 7. A packaging material comprising the gas barrier laminate according to any one of claims 1 to 5 laminated with a second base material by an adhesive.

Description

Gas barrier laminate and packaging material Technical Field The present invention relates to a gas barrier laminate and a packaging material obtained using the same. Background In packaging materials used for packaging foods, daily necessities, medicines, and the like, functions such as strength, fracture resistance, and gas barrier property are required in order to protect contents from impacts, oxygen, and moisture degradation, and the like, which are received during distribution, and the like. Since it is difficult to satisfy these necessary functions with one material, a laminate obtained by bonding different kinds of polymer materials is widely used as a packaging material. As a laminated film having gas barrier properties, for example, a gas barrier laminate is known in which a coating liquid for gas barrier containing an ammonium salt (a) of a polymer having a carboxyl group, a particulate polyvalent metal compound (B) and water, the content of the polyvalent metal compound (B) being 0.5 to 2.0 stoichiometric amount relative to the carboxyl group of the ammonium salt (a), and the average particle diameter of the polyvalent metal compound (B) being 4 μm or less is formed by coating the substrate and drying the coating liquid (for example, refer to patent document 1). In order to provide the gas barrier laminate disclosed in patent document 1 with the function as a packaging material for circulation, a laminate film of different resin types, which is obtained by providing an anchor coat layer on a biaxially stretched polyethylene terephthalate film, forming a coat layer on which a coating liquid for gas barrier is applied and drying, dry-laminating a biaxially stretched nylon film via a two-component adhesive on the surface on the coat layer side, and further dry-laminating a biaxially stretched nylon film and an unstretched polypropylene film via the same adhesive, was evaluated (see patent document 1 for example). On the other hand, in recent years, packaging materials that are not only functional but also recyclable have been desired. Only laminate films of different resin types, which are considered to be functional, have sounds that deteriorate the quality of recycled plastic, and laminate films of the same resin type, for example, packaging materials composed only of olefin resins are expected as recyclable packaging materials. When the coating liquid for gas barrier disclosed in patent document 1 is combined with a polyolefin resin film, although a desired gas barrier property can be obtained, flexibility tends to be poor, and in particular, cracks or the like may occur in the coating layer without following the bending or elongation of the polyolefin resin film. In addition, when the ammonium salt (a) of the polymer having a carboxyl group with a high molecular weight is used as the gas barrier coating liquid disclosed in patent document 1, the liquid stability is poor and the time period for which the gas barrier coating liquid can be used is short. When the ammonium salt (a) of the polymer having a carboxyl group of low molecular weight is used, film formation is impossible and the gas barrier property is poor. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2014-94972 Disclosure of Invention Problems to be solved by the invention The present invention aims to provide a gas barrier laminate which is excellent in balance between gas barrier properties and bendability and which is suitable for obtaining a recyclable packaging material, using a coating liquid for gas barrier which is excellent in liquid stability and film forming properties, and a plastic film such as a composite olefin. Solution for solving the problem The present inventors have found that a gas barrier laminate having an excellent balance between gas barrier properties and bendability can be obtained by combining a layer (B) having gas barrier properties, which contains a polyvalent metal compound in an amount within a specific range, with a layer (a) formed of an olefin-based substrate on which an inorganic layer is formed. Further, the present inventors have found that a gas barrier laminate having more excellent flexibility can be obtained by using, as the layer (B), a layer (B) containing a polyvalent metal compound in an amount within a specific range and containing a hydroxyl group-containing compound such as glycerin. That is, the present invention provides a gas barrier laminate comprising: (A) A layer (A) formed of an olefin-based substrate having an inorganic layer formed on at least one surface, and (B) A layer (B) containing an ammonium salt of a resin having a carboxyl group and a polyvalent metal compound having a chemical equivalent of 0.1 to 0.5 to the carboxyl group of the ammonium salt of the resin having a carboxyl group, The layer (B) contains an ammonium salt of a resin (P1) having a carboxyl group and a weight average molecular weight of 3,000-200,000 and