Kuraray Co., Ltd.

Naohiko Uchiumi

Kaoru Ikeda

Noriyuki Kida

Hiroyuki Shindome

Kazushige Ishiura

Kenichi Hamada

Tomohiro Ono

Tetsuya Hara

Masaji Kato

Syukiti Kawamura

Sachie Yaginuma

Hiroyuki Shimo

Kazuhiko Maekawa

Mamoru Omoda

Takashi Wakui

Yukio Ozeki

Kenji Nakano

Atsushi Itou

A melt-molded article containing an EVOH resin composition of low acetic acid odor and good long run workability is provided.

Melt-molded article containing an ethylene-vinyl alcohol copolymer resin composition of low carboxylic acid content

An ethylene-vinyl alcohol copolymer resin having low odor of acetic acid and good long-run workability is provided. The ethylene-vinyl alcohol copolymer resin which contains an alkali metal salt (A) and has a very low extractable carboxylate content is obtained by a method including contacting the ethylene-vinyl alcohol copolymer resin with an aqueous solution containing carbon dioxide gas.

Ethylene-vinyl alcohol copolymer resin composition of low carboxylic acid content

The present invention provides a process for producing pellet of EVOH comprising the steps of introducing an EVOH solution containing alcohol into an apparatus, contacting the solution with water in the apparatus to let out the alcohol with water and then letting out an EVOH hydrous composition from the above-mentioned apparatus (step 1); cutting the EVOH hydrous composition let out therefrom to obtain EVOH hydrous composition pellets (step 2); introducing the obtained EVOH hydrous composition pellets into a dryer to reduce a water content thereof (step 3); melt-kneading the pellets, whose water content is reduced, in an extruder (step 4); and cutting EVOH discharged from the extruder to obtain the pellet of EVOH (step 5). Thus, the EVOH hydrous composition obtained by removing alcohol without deteriorating the environment can be efficiently dried, and pellets having less thermal degradation in drying and a uniform shape can be obtained.

Process for producing pellet of ethylene/vinyl alcohol copolymer

A blow molded container made of an ethylene-vinyl alcohol copolymer resin composition, wherein the composition contains 0.1 to 20 &#x3bc;mol/g, in terms of alkali metal, of an alkali metal salt (A), 0 to 2 &#x3bc;mol/g of a carboxylate radical (C1) which is extracted through an immersion treatment in water at 95&#xb0; C. for 10 hours, and 0 to 40 &#x3bc;mol/g of a carboxylate radical (C2) which is extracted through an immersion treatment in a 0.05 N aqueous sodium hydroxide solution at 95&#xb0; C. for 10 hours.

Blow molded container and method for producing the same

The present invention provides an ethylene-vinyl alcohol based copolymer (EVOH) having fundamentally improved thermal stability. The EVOH is characterized in that the proportion of ethylene units (III) is from 20 to 60 mole % with respect to the total (III+IV+V) of ethylene units (III), vinyl alcohol units (IV), and vinyl ester units (V), and the proportion of the total (I+II) of carboxylic acids units (I) and lactone ring units (II) in copolymer terminals with respect to the total (III+IV+V) is 0.12 mole % or less. The EVOH can be obtained by, for example, contacting a reducing agent with an ethylene-vinyl ester based copolymer before saponification and/or EVOH after saponification.

Ethylene-vinyl alcohol based copolymer and method for production thereof

A method for producing an ethylene-vinyl alcohol copolymer resin composition, wherein an ethylene-vinyl alcohol copolymer resin is contacted with an aqueous solution containing both carbon dioxide gas and at least one additive selected from the group consisting of an alkali metal salt (A) and a boron compound (B). The present invention can provide an environmentally friendly method for producing an EVOH resin composition, the method releasing no carboxylic acid such as acetic acid to the ambient atmosphere. In addition, the invention can provide an EVOH resin composition which emits less smell and is superior also in long-run workability.

Ethylene-vinyl alcohol copolymer resin compositions and process for production thereof

The present invention provides a resin composition which comprises EVOH and a thermoplastic resin other than EVOH and which generates less odor and therefore is suitable for food packaging applications. The invention also provides an environmentally friendly method for producing a resin composition, without releasing any carboxylic acid such as acetic acid to the peripheral environment. A resin composition containing less carboxylate group is obtained by contacting an ethylene-vinyl alcohol copolymer resin with an aqueous solution containing both carbon dioxide gas and at least one additive selected from the group consisting of an alkali metal salt (A) and a boron compound (B) and then melt kneading with a thermoplastic resin (G) other than EVOH.

Resin composition and method for producing the same

The present invention provides a resin composition including an ethylene-vinyl alcohol copolymer (EVOH) and a polyamide resin and having outstanding properties in terms of long-term run stability, appearance, and hot water resistance in melt molding. In this resin composition, 70 mol % or more of all the terminal ends of the polyamide resin are blocked with units including an imide structure. At least a portion of the units containing an imide structure may be units containing a cyclic imide structure.

The present invention is directed to a resin composition superior in barrier properties and also superior in flexibility, secondary processability and interlayer adhesiveness. The present invention is also directed to an environmentally friendly method for producing a resin composition, the method releasing no carboxylic acid such as acetic acid to the peripheral environment. The invention provides an EVOH resin composition (F) which has a content of an alkali metal salt (A), in terms of the alkali metal, of 0.1 to 20 &#x3bc;mol/g and a content of a carboxyl acid or its salt (C), in terms of carboxylate radical, of 2 &#x3bc;mol/g or less and which has an ethylene content of 5 to 60 mol % and a saponification degree of from 80 to 99 mol %. In addition, the invention provides a resin composition comprising the EVOH resin composition (F) and an EVOH having an ethylene content of 5 to 60 mol % and a degree of saponification of 99.2 to 100 mol %.

A process for the preparation of an acrylic acid ester polymer, includes carrying out polymerization of an acrylic acid ester or block copolymerization of an acrylic acid ester and another (meth)acrylic monomer in the presence of an organolithium compound and an organoaluminum compound represented by the following formula (I):AlRRR&#x2003;&#x2003;(I)wherein Rrepresents an alkyl group having at least 3 carbon atoms, an alkoxy group having at least 3 carbon atoms or an aryloxy group, Rand Reach independently represent an aryloxy group or may be coupled together to form an arylenedioxy group. The process makes it possible to heighten the reaction rate and living properties upon polymerization and heighten the block formation efficiency upon block copolymerization.

Preparation process of acrylic acid ester polymer

The invention is to provide an aqueous dispersion having good adhesiveness, especially airtight adhesiveness to various substrates, and having good storage stability, good weather resistance and good hydrophobicity. The aqueous dispersion comprises a block copolymer composed of polymer blocks (A) consisting essentially of olefin monomer units and polymer blocks (B) comprising from 2 to 100 mol % of units of vinyl monomers having a carboxyl group or a carboxylic acid anhydride group and from 0 to 98 mol % of units of other vinyl comonomers capable of copolymerizing with the vinyl monomers, dispersed in an aqueous solution of at least 0.05 equivalents, relative to the carboxyl group or the carboxylic acid anhydride group, of a basic substance.

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Okayama, Japan

Naohiko Uchiumi