Maro Publications

Ethylene Vinyl Alcohol Copolymers
EVOH

Notes

Patent Abstracts

Patent Titles

*8/19/2013 
from 8/19/2013

Maro Encyclopedia

Barrier Materials

Polyethylene (PE) Copolymers

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Notes

2. “It is known that ethylene-vinyl alcohol copolymers (EVOH) have an excellent gas barrier property. Certain compositions exhibiting low gas permeability performance composed of thermoplastic resin-based blends such as a polyethylene terephthalate and vinyl alcohol-ethylene copolymer (PET/EVOH), where one thermoplastic resin is layered over the other layer to form plural layers by molding, are disclosed in Japanese Patent Application No. 7-55929. However, since these materials are thermoplastic resin/thermoplastic resin blends, while they are superior in gas barrier performance, they lack flexibility, and therefore, such films are subject to failure if they are used in a vehicle tire which is subject to significant stress and flexing.” [EVOH, US Patent 8,470,922 (6/25/2013)]

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1. “Ethylene vinyl alcohol (EVOH) is a formal copolymer of ethylene and vinyl alcohol. Because the latter monomer mainly exists as its tautomer acetaldehyde, the copolymer is prepared by polymerization of ethylene and vinyl acetate to give the ethylene vinyl acetate (EVA) copolymer followed by hydrolysis. The plastic resin is commonly used in food applications, and it has lately found application in plastic gasoline tanks for automobiles. Its primary purpose is to provide barrier properties, primarily as an oxygen barrier for improved food packaging shelf life and as a hydrocarbon barrier for fuel tanks. EVOH is typically coextruded or laminated as a thin layer between cardboard, foil, or other plastics. EVOH copolymer is defined by the mole % ethylene content: lower ethylene content grades have higher barrier properties; higher ethylene content grades have lower temperatures for extrusion.”

“EVOH is used in a liquid embolic system in interventional radiology, e.g. in Onyx.[3] Dissolved in dimethyl sulfoxide (DMSO) and mixed with a radiopaque substance, ethylene vinyl alcohol copolymer is used to embolize blood vessels.”

(EVOH, Wikipedia, 8/19/2013)

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Patent Abstracts

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Patent Titles

6/25/2013

1. 8,470,922 
Ethylene-vinyl alcohol based thermoplastic elastomers and vulcanizates 

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Interested!!
Bookmark this page to follow future developments!.
(RDC 7/16/2012)

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Roger D. Corneliussen
Editor
www.maropolymeronline.com

Maro Polymer Links
Tel: 610 363 9920
Fax: 610 363 9921
E-Mail: cornelrd@bee.net  

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Copyright 2013 by Roger D. Corneliussen.
No part of this transmission is to be duplicated in any manner or forwarded by electronic mail without the express written permission of Roger D. Corneliussen
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* Date of latest addition; date of first entry is 8/19/2013.