Ethylene-vinyl alcohol copolymer composition, pellets, and multilayer structure

Patent metadata

Field	Value
Publication number	US-11613642-B2
Application number	US-201916678273-A
Country	US
Kind code	B2
Filing date	Nov 8, 2019
Priority date	Jun 27, 2017
Publication date	Mar 28, 2023
Grant date	Mar 28, 2023

Abstract

An ethylene-vinyl alcohol copolymer composition contains: (A) an ethylene-vinyl alcohol copolymer including two or more types of ethylene-vinyl alcohol copolymers having different ethylene structural unit contents; and (B) an iron compound; wherein the iron compound (B) is present in an amount of 0.01 to 5 ppm on a metal basis based on the weight of the ethylene-vinyl alcohol copolymer composition. The ethylene-vinyl alcohol copolymer composition is substantially free from coloration and excellent in heat stability.

First claim

The invention claimed is:

1. An ethylene-vinyl alcohol copolymer composition comprising:
(A) an ethylene-vinyl alcohol copolymer comprising:
(A1) an ethylene-vinyl alcohol copolymer having an ethylene structural unit content of less than 35 mol %; and
(A2) an ethylene-vinyl alcohol copolymer having an ethylene structural unit content of not less than 35 mol %; and

(B) an iron compound;
wherein the ethylene-vinyl alcohol copolymer (A) has an ethylene structural unit content of 20 to 60 mol %, and
wherein the iron compound (B) is present in an amount of 0.01 to 1 ppm on a metal basis based on a weight of the ethylene-vinyl alcohol copolymer composition.

2. The ethylene-vinyl alcohol copolymer composition according to claim 1 , wherein a difference in ethylene structural unit content between an ethylene-vinyl alcohol copolymer having a highest ethylene structural unit content and an ethylene-vinyl alcohol copolymer having a lowest ethylene structural unit content out of the two or more ethylene-vinyl alcohol copolymers in the ethylene-vinyl alcohol copolymer (A) is not less than 2 mol %.

3. The ethylene-vinyl alcohol copolymer composition according to claim 1 , wherein a weight ratio of the ethylene-vinyl alcohol copolymer (A1) to the ethylene-vinyl alcohol copolymer (A2) is (A1)/(A2)=90/10 to 10/90.

4. Pellets comprising the ethylene-vinyl alcohol copolymer composition according to claim 1 .

5. A multilayer structure comprising a layer which comprises the ethylene-vinyl alcohol copolymer composition according to claim 1 .

Assignees

• Mitsubishi Chem Corp

Inventors

• USUI Shintaro
• Nishimura Daichi
• Ikeshita Minako

Classifications

• C08K2003/328

  Phosphates of heavy metals · CPC title

• B32B27/34

  comprising polyamides · CPC title

• B29B9/06

  in the form of filamentary material, e.g. combined with extrusion · CPC title

• B29K2023/086

  EVOH, i.e. ethylene vinyl alcohol copolymer · CPC title

• B32B25/14

  comprising {synthetic rubber copolymers (B32B25/18 and B32B25/20 take precedence)} · CPC title