Resin composition, multilayer sheet, packaging material and container

Patent metadata

Field	Value
Publication number	US-2016244601-A1
Application number	US-201415026673-A
Country	US
Kind code	A1
Filing date	Oct 2, 2014
Priority date	Oct 2, 2013
Publication date	Aug 25, 2016
Grant date	—

Abstract

Provided is a resin composition that exhibits inhibited flow marks, coloring and odor in a long-run operation, and is superior in heat stretching properties. The resin composition contains: an ethylene-vinyl alcohol copolymer (EVOH) (A) having an ethylene content of 20 mol % or greater and 50 mol % or less; EVOH (B) having an ethylene content of 30 mol % or greater and 60 mol % or less; and a saturated carbonyl compound (C) having 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 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 or greater and 95/5 or less, and 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

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) comprising 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 comprising from 1 to 10 carbon atoms or an alkoxy group comprising 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 a 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
forming the multilayer sheet according to claim 6 by a heat-stretching process.

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

Assignees

• Kuraray Co

Inventors

• Kawai Hiroshi

Classifications

• B32B2439/70

  Food packaging · CPC title

• B29C48/08

  flexible, e.g. films · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08L23/16

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

• B29C51/10

  Forming by pressure difference, e.g. vacuum · CPC title