The Nippon Synthetic Chemical Industry Co., Ltd.

Shinji Okamoto

Kouji Yamada

Yoshiharu Nagao

Yasufumi Beniya

Keisuke Fujimura

Akio Harao

Tomonori Yoshida

Hiroki Masumoto

The present invention provides a resin composition which is excellent in gas-barrier properties after a hot-water treatment and excellent in handling properties without increasing viscosity of the resin composition in a melt-kneading step at forming. The invention provides a resin composition containing a thermoplastic resin (A) and a partially dehydrated product or completely dehydrated product (B) of hydrated carboxylic acid salt.

Resin composition, melt-formed article, multilayer structure, and process for producing resin composition

An ethylene-vinyl alcohol copolymer alcohol solution comprising an ethylene-vinyl alcohol copolymer and an alcohol having a carbon number of not greater than 4 is brought into contact with an aqueous solution of at least one additive selected from a carboxylic compound, a boron compound and a phosphoric compound to replace a part or all of the alcohol with water, whereby an ethylene-vinyl alcohol copolymer composition containing the additive is prepared. This preparation process makes it possible to efficiently replace the alcohol in the ethylene-vinyl alcohol copolymer alcohol solution with water, and homogeneously incorporate the thermal stabilizer in the composition.

Process for preparing ethylene-vinyl alcohol copolymer composition, and process for producing ethylene-vinyl alcohol copolymer pellets

An ethylene-vinyl alcohol copolymer (EVOH) composition preparation process is provided, which comprises the steps of: feeding an EVOH alcohol solution into a tower type apparatus, the EVOH alcohol solution comprising 100 parts by weight of an EVOH and not less than 300 parts by weight of an alcohol having a carbon number of not greater than 4; bringing the EVOH alcohol solution into contact with water, and feeding out a part of the alcohol together with water from the apparatus to provide an EVOH water/alcohol mixture solution comprising 100 parts by weight of the EVOH, 10 to 200 parts by weight of the alcohol and 50 to 200 parts by weight of water; bringing the EVOH water/alcohol mixture solution into contact with water in an agitator container with stirring, and feeding out a part or all of the alcohol together with water from the container to provide an EVOH composition comprising 100 parts by weight of the EVOH, less than 10 parts by weight of the alcohol and 20 to 100 parts by weight of water. This preparation process makes it possible to efficiently replace the alcohol in the EVOH alcohol solution with water to provide a lower water content EVOH composition.

The present invention provides a resin composition of a saponified ethylene-vinyl ester copolymer can provide a molded product including layer of the resin composition with less thickness variation and excellent gas-barrier properties, even if the layer is subjected to stretch forming such as deep drawing forming and vacuum-pressure forming where the layer is applied with different tension from side to side thereof in short time. The resin composition comprises an EVOH resin having ethylene content of 20 to 60 mol % and a PVA having 1,2-diol structural unit in a side chain. The present invention also provides a multilayer structure using the resin composition.

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Osaka, Japan

Shinji Okamoto