Kuraray Co., Ltd.

Kurarav Co., Ltd.

Akimasa Aoyama

Takeshi Moritani

Takuji Okaya

Satoshi Hirofuji

Kiyoshi Yonezu

Junnosuke Yamauchi

Toshiaki Sato

Taichi Negi

Takanori Kitamura

Fumio Nakahara

Tetsuya Katayama

Yoshinari Tanaka

Hisamichi Yanai

Yukio Ozeki

Toshio Tsuboi

Katsumi Shimizu

Kaoru Ikeda

Hitoshi Maruyama

Takaharu Kawahara

Naoshi Nakagawa

Yukihiro Ohara

Kenji Satoh

Hidemasa Oda

Makio Tokoh

Toshinori Tsugaru

Junichi Uemura

A process for producing vinyl acetate polymers comprises, after polymerization of at least one monomer comprising vinyl acetate, adding a conjugated polyene having a boiling point of at least 20&deg; C. Saponified products of the vinyl acetate polymers obtained by this process can give molded articles causing little coloring and generation of gel-like agglomerates.

Resin composition comprising a saponified product of vinyl acetate polymer

This invention provides an ethylene-vinyl alcohol copolymer composition having specific flow characteristics in the relationship between the heating time and the extrusion rate measured with a capillary rheometer (Koka Flow Tester), and a multilayered structure utilizing the same. From the EVOH composition according to the present invention, can be obtained a molded article, particularly a multilayered structure, having an excellent appearance; more particularly, in a continuous melt molding operation over a long period, a molded article, particularly a multilayered structure, having an excellent appearance can always be obtained without worsening the appearance with running time.

Multilayered structure containing an ethylene-vinyl alcohol layer

Process for producing ethylene-vinyl ester copolymers using a polymerization solvent of a dialkyl sulfoxide (process X); process for producing ethylene-vinyl alcohol copolymer by liquid phase saponification using a solvent of a dialkyl sulfoxide (process Y); and process for producing shaped articles which comprises contacting the ethylene-vinyl alcohol copolymer obtained by the process Y, or that obtained by saponifying the ethylene-vinyl ester copolymer obtained by process X, to a non-solvent for ethylene-vinyl alcohol copolymer. Ethylene-vinyl ester copolymers having a wide range of ethylene content and higher degree of polymerization than that with solution polymerization using methanol. The rate of saponification is higher than that with single solvent system of lower alcohol. Production cost is low, because production process of polymer is directly connected to that of shaped articles utilizing the polymer.

Process for producing ethylene-vinyl ester copolymers, ethylene-vinyl

Provided are compositions comprising a saponified product of an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 80 mol % and a saponification degree of vinyl acetate component of at least 95 mol %, said composition containing 20 to 200 ppm as converted to alkali metal of an alkali metal acetate, 30 to 250 ppm of acetic acid, and 5 to 500 ppm as converted to phosphate ion of phosphoric acid or an alkali metal hydrogenphosphate, and having a content ratio of acetic acid/alkali metal acetate of 0.1 to 1 and the flow characteristic that the extrusion rate does not substantially increase for at least 10 hours in the relationship between the heating time and the extrusion rate with a capillary rheometer (Koka Flow Tester) at at least one temperature 10.degree. to 80.degree. C. above the melting point. Also provided are multilayered containers comprising as the innermost layer a layer formed by the use of the above composition, and packages comprising such containers containing a liquid article or paste article.

Multilayered container

An aqueous dispersion comprising a dispersoid of an ethylene-vinyl alcohol copolymer having an ethylene content of 15 to 65 mole % and a dispersion stabilizer of a saponified product of an ethylene-vinyl ester copolymer having an ionic group and having an ethylene content of 10 to 70 mole % and a saponification degree of at least 80%. According to the present invention, aqueous dispersions with high solid concentration and having excellent stability during storage or upon use. The film obtained by applying and then drying the aqueous dispersion has excellent gas barrier properties.

Aqueous dispersion and substrate coated with the same

Process for producing ethylene-vinyl alcohol copolymers

A multilayered container comprising an intermediate layer of a resin composition (A) which comprises 50-95% by weight of a specific EVOH, and 50-5% by weight of an inorganic filler, and inner and outer layers of a moisture resistant thermoplastic resin (B), at least the body wall part of the container comprising multiplicity of regions in which substantially 2-dimensional thin layers of the inorganic filler extend parallel with the wall surface and laminated with each other, said layer of said resin composition (A) having a specific moisture permeability. The multilayered container can readily be prepared by thermoforming from the corresponding multilayered structure. Food packages obtained by filling the multilayered container of the present invention with food, sealing it and then sterilizing the package under a condition where heat and moisture act at the same time as in retorting are resistant against impermeation of oxygen that would deteriorate the food contained therein, thus exhibiting excellent storage capability, and have good container appearance.

Multilayered container and package utilizing the same

Composition

Ethylene-vinyl alcohol copolymers wherein ethylene content is 10-70 mol % diad syndiotacticity is not less than 55 mol %, and intrinsic viscosity [.eta.] is not less than 0.05 l/g when measured with a mixed solvent of 85 weight % of phenol and 15 weight % of water at 30 20 C., which show less decrease of resistance to gas permeation under high temperature and high humidity, while retaining resistance to get permeation under low humidity, transparency and melt moldability, and moldings and laminates formed thereof.

Ethylene-vinyl alcohol copolymers, moldings and laminates

Methylene-vinyl alcohol copolymer composition

The present invention relates to resin compositions and laminates using saponified ethylene-vinyl acetate copolymers containing a polyether component. Formed products and laminates obtained from the resin compositions are flexible, excellent in flexural fatigue resistance and gas barrier properties and extremely useful as flexible laminates.

Resin compositions, laminates and block copolymers

There is provided a laminate having good gas barrier properties which comprises at least one barrier layer of modified ethylene-vinyl alcohol copolymer containing 0.1 to 5 mol % of pyrrolidone ring-containing units and 20 to 55 mol % of ethylene units, with the degree of saponification of the vinyl acetate component being at least 98 mol %, and at least one layer of thermoplastic resin. This laminate is superior in drawability, and can be made by drawing into bottles, cups, and the like which exhibit excellent clarity, appearance, and gas barrier properties.

Laminate having good gas barrier properties with barrier layer of

There is provided a coating material made of a saponification product of a modified ethylene-vinyl acetate copolymer containing a cross-linkable olefinically unsaturated monomer. The saponification product is characterized by its intrinsic viscosity not greater than 0.7 dl/g which is measured at 20.degree. C. using phenol containing 15 wt % of water as a solvent. This polymer is readily soluble in solvents, and the resulting solution can have concentration as high as 20 to 50 wt % and provide coating film which is as strong as that obtained from the conventional EVOH having a high degree of polymerization.

Coating material

A melt molding material which comprises a saponified product of a silicon-containing ethylene-vinyl acetate copolymer. When this melt molding material is formed into a sheet, said sheet is excellent in extensibility and thus suitable for deep forming. The decrease in gas barrier properties is small even under high moisture conditions, and its stress cracking resistance is excellent.

Growing community of inventors

Kurashiki, Japan

Akimasa Aoyama