Resin composition, multilayer sheet, packaging material and container

Patent metadata

Field	Value
Publication number	US-10093795-B2
Application number	US-201415026673-A
Country	US
Kind code	B2
Filing date	Oct 2, 2014
Priority date	Oct 2, 2013
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

A resin composition includes an ethylene-vinyl alcohol copolymer (EVOH) (A) having an ethylene content of 20 to 50 mol %, an EVOH (B) having an ethylene content of 30 to 60 mol %, and a saturated carbonyl compound (C) having 3 to 8 carbon. The saturated carbonyl compound (C) is a saturated aldehyde, a saturated ketone, or a combination thereof. A value obtained by subtracting the ethylene content of the EVOH (A) from the ethylene content of the EVOH (B) is 8 mol % or greater. The mass ratio (A/B) of the EVOH (A) to the EVOH (B) is 60/40 to 95/5. The content of the saturated carbonyl compound (C) with respect to the resin content is 0.01 ppm or greater and less than 100 ppm.

First claim

The invention claimed is:

1. A resin composition, comprising:
an ethylene-vinyl alcohol copolymer (A) having an ethylene content of 20 mol % or greater and 50 mol % or less;
an ethylene-vinyl alcohol copolymer (B) having an ethylene content of 30 mol % or greater and 60 mol % or less; and
a saturated carbonyl compound (C) having from 3 to 8 carbon atoms,
wherein:
the saturated carbonyl compound (C) is a saturated aldehyde (C-1), a saturated ketone (C-2) or a combination thereof,
a value obtained by subtracting the ethylene content of the ethylene-vinyl alcohol copolymer (A) from the ethylene content of the ethylene-vinyl alcohol copolymer (B) is 8 mol % or greater,
a mass ratio (A/B) of the ethylene-vinyl alcohol copolymer (A) to the ethylene-vinyl alcohol copolymer (B) is 60/40 or greater and 95/5 or less, and
a content of the saturated carbonyl compound (C) with respect to a resin content is 0.01 ppm or greater and less than 100 ppm.

2. The resin composition according to claim 1 , wherein a difference between a melting point of the ethylene-vinyl alcohol copolymer (A) and a melting point of the ethylene-vinyl alcohol copolymer (B) is 15° C. or greater.

3. The resin composition according to claim 1 , wherein:
the ethylene-vinyl alcohol copolymer (B) has a structural unit represented by formula (1):

wherein,
R 1 , R 2 , R 3 and R 4 each independently represent a hydrogen atom, a hydrocarbon group having from 1 to 10 carbon atoms or an alkoxy group having from 1 to 10 carbon atoms,
wherein
a part or all of hydrogen atoms in the hydrocarbon group are unsubstituted or substituted with a hydroxyl group, an alkoxy group, a carboxyl group or a halogen atom,
R 1 and R 2 optionally represent a ring structure through binding with each other, and
a percentage content of the structural unit with respect to the total vinyl alcohol units is 0.3 mol % or greater and 40 mol % or less.

4. The resin composition according to claim 1 , wherein the saturated carbonyl compound (C) is the saturated aldehyde (C-1), and the saturated aldehyde (C-1) is propanal, butanal, hexanal or a combination thereof.

5. The resin composition according to claim 1 , wherein the saturated carbonyl compound (C) is the saturated ketone (C-2), and the saturated ketone (C-2) is acetone, methyl ethyl ketone, 2-hexanone or a combination thereof.

6. A multilayer sheet, comprising:
a barrier layer formed of the resin composition according to claim 1 ; and
a thermoplastic resin layer laminated on at least one face of the barrier layer.

7. The multilayer sheet according to claim 6 , wherein the barrier layer and the thermoplastic resin layer are laminated by a coextrusion molding process.

8. A packaging material, obtained by a process comprising
subjecting the multilayer sheet according to claim 6 to a heat-stretching process.

9. A container, obtained by a process comprising
subjecting the multilayer sheet according to claim 6 to a vacuum or pressure forming process.

Assignees

• Kuraray Co

Inventors

• Kawai Hiroshi

Classifications

• C08L29/04

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title

• C08L23/0861

  Saponified copolymers, e.g. ethylene vinyl alcohol copolymers · CPC title

• B32B27/06

  as the main or only constituent of a layer, {which is} next to another layer of {the same or of} a {different material (next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08)} · CPC title

• B29C48/08

  flexible, e.g. films · CPC title

• C08L23/16

  Ethylene-propylene or ethylene-propylene-diene copolymers · CPC title