Multilayer structure, resin composition for adhesive resin layer, and multilayer structure production method

Patent metadata

Field	Value
Publication number	US-11845882-B2
Application number	US-201916249385-A
Country	US
Kind code	B2
Filing date	Jan 16, 2019
Priority date	Jul 27, 2016
Publication date	Dec 19, 2023
Grant date	Dec 19, 2023

Abstract

A multilayer structure includes an adhesive resin layer provided between a thermoplastic resin layer and a gas barrier resin layer, wherein the adhesive resin layer is formed from a resin composition containing a polyolefin resin (A) containing at least one of a carboxyl group and an acid anhydride group, and a fatty acid zinc salt (B), wherein the fatty acid zinc salt (B) is present in the resin composition in a proportion of 40 to 250 ppm on a metal basis based on the amount of the adhesive resin layer.

First claim

The invention claimed is:

1. A multilayer structure comprising:
a thermoplastic resin layer;
a gas barrier resin layer; and
an adhesive resin layer provided between the thermoplastic resin layer and the gas barrier resin layer;
wherein the adhesive resin layer comprises a resin composition comprising:
(A) a polyolefin resin containing at least one of a carboxyl group and an acid anhydride group; and
(B) one or more fatty acid zinc salts;
wherein the one or more fatty acid zinc salts (B) is present in the resin composition in a proportion of 80 to 250 ppm on a metal basis based on an amount of the adhesive resin layer;
wherein the resin composition for the adhesive resin layer is free from a hydrotalcite; and
wherein the resin composition for the adhesive resin layer has an absorbance ratio (a/b) of 0.005 to 0.5, wherein (a) is an absorbance at a peak attributable to C═O stretching vibration observed at around 1710 cm −1 and (b) is an absorbance ata peak attributable to C—H bending vibration observed at around 1450 cm −1 in Fourier transform infrared spectroscopy performed on the resin composition by a transmission method.

2. The multilayer structure according to claim 1 , wherein the one or more fatty acid zinc salts (B) present in the resin composition for the adhesive resin layer has a carbon number of 4 to 28.

3. The multilayer structure according to claim 1 , wherein the one or more fatty acid zinc salts (B) present in the resin composition for the adhesive resin layer has a molar mass of 200 to 1000 g/mol.

4. The multilayer structure according to claim 1 , wherein a gas barrier resin as a material for the gas barrier resin layer comprises at least one of a saponified ethylene-vinyl ester copolymer and a polyamide resin.

5. The multilayer structure according to claim 1 , which has an overall thickness of 10 to 5000 μm.

6. The multilayer structure according to claim 1 , wherein a thickness ratio between the gas barrier resin layer and the adhesive resin layer is (gas barrier resin layer/adhesive resin layer)=10/90 to 99/1.

7. The multilayer structure according to claim 1 , wherein the one or more fatty acid zinc salts (B) is present in the resin composition in a proportion of 80 to 100 ppm on a metal basis based on an amount of the adhesive resin layer.

8. A resin composition for an adhesive resin layer, the resin composition comprising:
(A) a polyolefin resin containing at least one of a carboxyl group and an acid anhydride group; and
(B) one or more fatty acid zinc salts;
wherein the one or more fatty acid zinc salts (B) is present in a proportion of 80 to 250 ppm on a metal basis based on an amount of the resin composition;
wherein the resin composition for the adhesive resin layer is free from a hydrotalcite; and
wherein the resin composition for the adhesive resin layer has an absorbance ratio (a/b) of 0.005 to 0.5, wherein (a) is an absorbance at a peak attributable to C═O stretching vibration observed at around 1710 cm −1 and (b) is an absorbance ata peak attributable to C—H bending vibration observed at around 1450 cm −1 in Fourier transform infrared spectroscopy performed on the resin composition by a transmission method.

9. The multilayer structure according to claim 1 , wherein a proportion of the polyolefin resin (A) is not less than 70 wt. % in the resin composition for the adhesive resin layer.

10. The resin composition for an adhesive resin layer according to claim 8 , wherein the one or more fatty acid zinc salts (B) is present in the resin composition in a proportion of 80 to 100 ppm on a metal basis based on an amount of the resin composition.

11. A method of producing the multilayer structure according to claim 1 , comprising:
preparing a thermoplastic resin for the thermoplastic resin layer;
preparing a gas barrier resin for the gas barrier resin layer;
preparing a resin composition for the adhesive resin layer, the resin composition comprising a polyolefin resin (A) containing at least one of a carboxyl group and an acid anhydride group, and 80 to 250 ppm of one or more fatty acid zinc salts (B) on a metal basis based on an amount of the resin composition; and
forming the thermoplastic resin layer, the adhesive resin layer, and the gas barrier resin layer from the thermoplastic resin, the resin composition, and the gas barrier resin, respectively, by a coextrusion method or a coinjection molding method.

12. The method of producing the multilayer structure according to claim 11 , wherein, in the preparation of the resin composition, the one or more fatty acid zinc salts (B) is present in the resin composition in a proportion of 80 to 100 ppm on a metal basis based on an amount of the resin composition.

Assignees

• Nippon Synthetic Chem Ind Co Ltd
• Mitsubishi Chem Corp

Inventors

• Komuro Ryohei

Classifications

• C09J123/26 Primary

  modified by chemical after-treatment · CPC title

• B29B9/12

  characterised by structure or composition · CPC title

• B32B7/12

  using interposed adhesives or interposed materials with bonding properties · CPC title

• B32B27/08

  of synthetic resin · CPC title

• B32B27/18 Primary

  characterised by the use of special additives · CPC title