Kuraray Co., Ltd.

Naokiyo Inomata

Seiji Tanimoto

Masaki Kato

Hiroyuki Shindome

Naoyuki Himi

Kouichi Nogura

Chouji Suga

Kouichi Fujie

Mitsuo Ootani

Naoki Fujiwara

Osamu Kazeto

Toshio Tuboi

The present invention relates to a resin composition having an ethylene-vinyl alcohol copolymer (EVOH) component and a multi-layered structure containing the resin composition.

Resin composition of good long-run workability comprising ethylene-vinyl alcohol copolymer

A resin composition of an ethylene-vinyl alcohol copolymer adheres little to dies and ensures good long-run workability and self-purgeability and its shaped articles have good appearance with few voids and show diminished yellowing.

Ethylene-vinyl alcohol copolymer resin composition of improved long-run workability, and its shaped articles

A dispersion stabilizer for suspension polymerization of a vinyl compound contains a modified saponified vinyl ester copolymer (A) having an ethylene content of 1 to 20 mol %, a degree of saponification of 90 mol % or more and a degree of polymerization of 100 to 3,000, a saponified vinyl ester polymer (B) having a degree of saponification of 60 to 90 mol % and a degree of polymerization of 600 to 4,000, and a saponified vinyl ester polymer (C) having a degree of saponification of 30 to 60 mol % and a degree of polymerization of 100 to 600, and in which a component (A)/&lcub;component (B)&plus;component (C)&rcub; weight ratio if 5/95 to 40/60. The dispersion stabilizer for suspension polymerization of the vinyl compound exhibits quite excellent suspension polymerization stability. Further, the suspension polymerization of a vinyl compound using this dispersion stabilizer can produce a resin having a high bulk density minimizes the formation of milky turbid waste water.

Dispersion stabilizer for suspension polymerization of vinyl compound

Provided is a polyvinyl ester resin emulsion which has high viscosity and has good water resistant adhesiveness, heat-resistant adhesiveness, hot water-resistant adhesiveness and storage stability, especially high-temperature storage stability, and which has good film-forming ability and is readily formed into transparent films. The emulsion is produced in a method of polymerizing a vinyl ester monomer in a mode of emulsion polymerization in the presence of a polyvinyl alcohol serving as protective colloid and in the presence of a water-insoluble, hydroxyl group-containing compound.

Method for producing polyvinyl ester resin emulsion

A dispersion stabilizer for suspension polymerization of a vinyl compound containing a vinyl alcohol polymer (A) having a content of an ethylene unit of 0.5 to 10 mol %, a degree of saponification of 60 mol % or more and a degree of polymerization of 600 or more and a vinyl alcohol polymer (B) selected from the group consisting of a vinyl alcohol polymer (B1) having a content of an ethylene unit of 0.5 to 10 mol %, a degree of saponification of 20 to 80 mol % and a degree of polymerization of 100 to 600, a vinyl alcohol polymer (B2) having a degree of saponification of 20 to 60 mol % and a degree of polymerization of 100 to 600 and a vinyl alcohol polymer (B3) having a content of an ethylene unit of 0.5 to 10 mol %, a degree of saponification of 90 mol % or more and a degree of polymerization of 1,000 or more.

A polyvinyl alcohol having at least 1.9 mol % of 1,2-glycol bonds is used as a dispersant for emulsion polymerization or a dispersant for suspension polymerization, and this ensures good polymerization stability even when its amount used is reduced. The aqueous emulsion comprising the polyvinyl alcohol is resistant to water and the viscosity of the aqueous emulsion depends little on ambient temperatures. The vinylic polymers obtained through suspension polymerization in the presence of the polyvinyl alcohol are yellowed little, and the waste water in the suspension polymerization pollutes little the environment.

Aqueous emulsion and dispersant for suspension polymerization of vinyl compounds

Disclosed are a resin composition comprising an ethylene-vinyl alcohol copolymer and a multi-layered structure comprising the resin composition. The resin composition comprises an ethylene-vinyl alcohol copolymer which contains from 500 to 2000 ppm, in terms of the metal, of an alkali metal salt (A) and from 0.05 to 4.5 &mgr;mols/g of a carboxylic acid (B), where the ratio of the content (&mgr;mol/g) of a carboxylic acid (b1) having a molecular weight of at least 75 and its salt to the total content (&mgr;mol/g) of the carboxylic acid (B) and its salt is at least 0.1; or comprises an ethylene-vinyl alcohol copolymer which contains from 500 to 2000 ppm, in terms of the metal, of an alkali metal salt (A), from 10 to 500 ppm of a carboxylic acid (b2) having a molecular weight of smaller than 75, and from 10 to 500 ppm, in terms of the phosphate radical, of a phosphate compound (C). The resin composition has extremely good adhesiveness, and its moldings have good appearances with few gels and fish eyes. When molded, the resin composition ensures good long-run workability and recyclability, and the recycled resin composition is yellowed little.

Resin composition comprising ethylene-vinyl alcohol copolymer with good interlayer adhesiveness

Provided is an aqueous emulsion comprising, as the dispersant, a polyvinyl alcohol containing from 1 to 15 mol % of ethylene units in the molecule and having a degree of hydrolysis of at least 95 mol %; and, as the dispersoid, a vinyl ester polymer. The aqueous emulsion is characterized in that, when its film is immersed in water at 20&deg; C. for 24 hours, the degree of water solubility of the film is at most 1.5%, and the degree of water absorption of the film is at most 30%, and that the ratio of the emulsion viscosity at 60&deg; C. (T ) to the emulsion viscosity at 20&deg; C. (T ) T /T is at most 2. The aqueous emulsion has good high-temperature viscosity stability (that is, this depends little on ambient temperatures and has good high-temperature storage stability), and has improved water resistance and improved low-temperature storage stability.

Aqueous emulsion and method for producing it

An acrylic molded product comprising an acrylic polymer coagulated material having excellent characteristics in impact resistance, optical properties, and hydrothermal resistance; an acrylic polymer coagulated material used for the preparation thereof; an composition comprising thereof; and a process for manufacture thereof; characterized by using an emulsion polymerization and a polymer with multiphase structured material comprising a hard phase and a soft phase and being freeze-coagulated.

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Kurashiki, Japan

Naokiyo Inomata