METHOD FOR PRODUCING ETHYLENE-VINYL ALCOHOL COPOLYMER RESIN COMPOSITION

WIPO Patent Application WO/2022/138858

A1

The present invention provides a method for producing an ethylene-vinyl alcohol copolymer resin composition in which an additive and an ethylene-vinyl alcohol copolymer hydrous pellet at 0-80°C are introduced into an extruder (X) and are melt-kneaded, wherein: the additive includes at least one type of additive selected from the group consisting of carboxylic acids, boron compounds, phosphate compounds, alkali metal salts, and alkaline-earth metal salts; the additive is added to the ethylene-vinyl alcohol copolymer inside the extruder (X); the temperature T0 of the molten product in the extruder (X) is 70-180°C; the cylinder temperature T1 of the extruder (X) is 65-175°C; T0 and T1 satisfy formula (1): 5≤T0-T1≤100; the water content of the hydrous pellet that is introduced into the extruder (X) is 20-60 mass%; and the water content of the hydrous resin composition immediately after discharge from the extruder (X) is 10-35 mass%. This production method makes it possible to highly efficiently dehydrate an ethylene-vinyl alcohol copolymer hydrous pellet and to obtain an EVOH resin composition with less foaming and with a good hue, in a method in which the ethylene-vinyl alcohol copolymer hydrous pellet and a minor component are melt-kneaded in an extruder and then discharged.

KATAHIRA ERIKO (JP)
KIDA NORIYUKI (JP)
SHIOTA HIROTAKA (JP)

PCT/JP2021/047995

June 30, 2022

December 23, 2021

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KURARAY CO (JP)

C08K3/32; C08J3/20; C08K3/38; C08K5/09; C08K5/098; C08L29/04

JP2002284811A	2002-10-03
JP2001098077A	2001-04-10
JP2020090646A	2020-06-11
JP2002284886A	2002-10-03
JP2010007042A	2010-01-14
JP2000239316A	2000-09-05
JP2002284811A	2002-10-03

SETOUCHI INTERNATIONAL PATENT FIRM (JP)

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